The energy barriers between the chair, boat, and twist conformations of cyclohexane are low enough (Fig.6) to make separation of the conformers impossible at room temperature. Chair conformations are the most stable conformations cyclohexane can form. H t ta 5 11 HI TV OU O II O IV V Identify the most stable chair conformation of the most stable isomer of 1-ethyl-3- isopropylcyclohexane. How value of energy of elecron becomes more negative and radius of orbit decreases with increase in the value of atomic number? Ring flips are easy and involve 3 main steps: Your email address will not be published. This suggests that the methyl group must be present at the equatorial position at the third carbon atom of the cyclohexane ring. In the chair conformation, the bond angle for the carbons is about 109.5 degrees which is very close to the ideal bond angle for the sp3 hybridized carbons. The most stable conformation is the one where the most bulky group is positioned equatorial. A Conformation of cyclohexane can refer to many 3-Dimensional shapes assumed by a Axial positions are vertical and either straight up or straight down. This leads to a staggered conformation in chair form, reducing torsional strain. How do you identify a stable chair? 2. The lower energy chair conformation is the one with three of the five substituents (including the bulky CH2OH group) in the equatorial position. Least stable chair Most stable chair - University of California, He also shares personal stories and insights from his own journey as a scientist and researcher. There are a few exceptions to this rule, however. In order to rotate the substituents onto different bonds, we must complete a ring flip. If the tert-butyl group is placed in the axial bond, then the chair has the highest energy, or the least stable conformation. We also use third-party cookies that help us analyze and understand how you use this website. The substituents on a chair can take axial and equatorial positions. This too is almost free of angle strain, but in contrast has torsional strain associated with eclipsed bonds at the four of the C atoms that form the side of the boat. Welcome to Livings Cented! These cookies track visitors across websites and collect information to provide customized ads. Therefore, it has both eclipsing and bond angle strains and hence is the least stable conformation of cyclohexane. The substituents on a chair can take axial and equatorial positions. What makes a conformer more stable? Chair conformations are the most stable conformations cyclohexane can form. In between Chair conformer and Boat conformer, Chair conformer is more stable than the boat conformer because boat conformation has more steric strains and torsional strains. Draw both chair conformation (ring-flip) and use the table to calculate the relative energy cost associated with each group in the axial position to determine the more stable chair conformation of each of the following compounds: This content is for registered users only. Again, looking at the cyclohexane structure you previously drew, add the substituents to the correct carbons in your chair. (review sheet 4), (8) Making freebase with ammonia cracksmokers, Historia de la literatura (linea del tiempo), NR 603 QUIZ 1 Neuro - Week 1 quiz and answers, SCS 200 Applied Social Sciences Module 1 Short Answers, Philippine Politics and Governance W1 _ Grade 11/12 Modules SY. If the tert-butyl group is placed in the axial bond, then the chair has the highest energy, or the least stable conformation. The chair conformation is more stable because it does not have any steric hindrance or steric repulsion between the hydrogen bonds. The gauche form is less stable than the anti form due to steric hindrance between the two methyl groups but still is more stable than the eclipsed formations. An additional cause of the higher energy of the boat conformation is that adjacent hydrogen atoms on the bottom of the boat are forced into eclipsed positions. The cookie is used to store the user consent for the cookies in the category "Other. By clicking Accept, you consent to the use of ALL the cookies. Start numbering from the carbon at the bottom right position and continue numbering clockwise. Therefore, option A is the correct answer. By clicking Accept all cookies, you agree Stack Exchange can store cookies on your device and disclose information in accordance with our Cookie Policy. Why Does Electrical Work Cause Changes in Internal Energy of the System? Which chair conformation is more stable? Along with the direction, it also does not matter where you start counting. The half chair, formed by raising the footrest of the chair, has five of the six C atoms in a plane and one C atom out of the plane. i-Pr is smaller but still quite large. In their first semester of organic chemistry, students will learn how to correctly draw chairs, and how to convert 2 dimensional cyclohexane molecules with substituents into both chair forms. These cookies help provide information on metrics the number of visitors, bounce rate, traffic source, etc. This results in less crowding around the ring and fewer opportunities for steric interactions. So the isopropyl-group should be in axial-down position in the first conformation and equatorial-down position after the ring flip. The more hydrogen atoms there are, the more stable the chair conformation will be. Consider the conformations of cyclohexane, chair, boat, twist boat. After doing so I am a little uncertain which of the conformations is the most stable. The second thing you need to consider is how many hydrogen atoms are attached to each carbon. You'll get a detailed solution from a subject matter expert that helps you learn core concepts. We currently do not have a feature to support diagrams/graphs and will be updating soon. After doing so I am a little uncertain which of the conformations is the most stable. Store it in an airtight container to keep it fresh for as long as possible. 11 HII IV This problem has been solved! Using a chair conformation to draw the most stable conformation of a substituted cyclohexane molecule The chair conformation is shown only by 6-membered rings. The A-value represents the difference in energy (G) between a group being axial/equatorial on a cyclohexane ring, thus, as a group gets bigger, its A-value increases, reflecting the increasingly high energy needed to flip the ring. The lower the number, the more stable the environment. Therefore, it has both eclipsing and bond angle strains and hence is the least stable conformation of cyclohexane. This conformation is also known as the chair form because it resembles a chair with four legs. The basic structure is shown below. This cookie is set by GDPR Cookie Consent plugin. This is because the chair conformation places all of the substituents in a equatorial position, while the boat conformation has some substituents in an axial position. (6 pt) Cl Least stable chair Most stable chair 1 1 1 0.6 kcal/mol!G = (c) For trans-1-chloro-4-methylcyclohexane (shown below), draw in bonds to CH3 and Cl groups as appropriate, to indicate the least and most stable chair conformers. The most stable chair conformation of glucose has the C-2, C-3, and C-4 hydroxyl groups all on equatorial positions. [ Note 1 ] Of course, with organic chemistry fresh in your mind,you can tell which hydroxyl groups are up and which are down in the diagram below (right?): But then which is the most stable? The tert-butyl group needs to be placed in the equatorial bond, as it is the lowest energy, or highest stability, conformation. Disubstituted Cyclohexanes Determining the more stable chair conformation becomes more complex when there are two or more substituents attached to the cyclohexane ring. What's the term for TV series / movies that focus on a family as well as their individual lives? Therefore, option A is the correct answer. Besides that, hes a hobbyist blogger and research writer. Step 6 Draw the Front Legs of the Chair. (Recall: the vinyl group is -CH=CH2.) Calculate the ring strain and compare it to the first chair. One reason that our program is so strong is that our . In his professional life, hes a real-estate businessman. The chair conformation is the most stable conformation of cyclohexane. What is difference between Incest and Inbreeding? Check your hand-drawn structures, I believe them to be wrong. Which Conformation is More Stable And Why? Chair is the most stable three dimensional conformation that a cyclohexane can take. ASK AN EXPERT. How can I detect a specific molecule on a surface? For cis-1-chloro-4-methylcyclohexane, draw the most stable chair conformation and determine the energy difference between the two chair conformers. Solution 1. Is Chair Conformation Always Most Stable? A Chair Flip Does Not A Diastereomer Make. Necessary cookies are absolutely essential for the website to function properly. This website uses cookies to improve your experience while you navigate through the website. Why is the boat conformation of cyclohexane less stable? cis-1,4-Di-tert-butylcyclohexane, however, adopts a twist-boat conformation. To learn more, see our tips on writing great answers. Finally, you need to take into account any intramolecular interactions that may be present. Is that correct? Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Starting in the very middle of your paper, draw the seat of the chair. What are the most stable chair conformations? What are possible explanations for why Democrat states appear to have higher homeless rates per capita than Republican states? Is chair or boat conformation more stable? The chair conformation is the most stable conformer. The half chair, formed by raising the footrest of the chair, has five of the six C atoms in a plane and one C atom out of the plane. When drawing chair conformations, the type of bond alternates. This cookie is set by GDPR Cookie Consent plugin. If the tert-butyl group is placed in the axial bond, then the chair has the highest energy, or the least stable conformation. Stability of Chair Conformations - Chairs will be more stable when grps in equatorial posns -- not bumping into anything (bumping is steric hinderance) - Axial posns are bumping into other axial posns; equatorial are not - The larger the grp, the more it What modification occurs when a small amount of p-divinylbenzene is added to the polymerization reaction of styrene to polystyrene? Remember that a dash means down and wedge means up. Which chair conformation is more stable? He created Livings Cented to assist people who want to organize their home with all the modern furniture, electronics, home security, etc. Among which chair conformation is most stable because it has negligible ring strains so, its potential energy is = 0 kcal/mol. Are the CH bonds the most stable in the chair or boat conformation of cyclohexane? Can I use milk instead of milk powder in chocolate? 3 Why is the boat conformation of cyclohexane less stable? Your email address will not be published. How to tell if my LLC's registered agent has resigned? 11 HII IV This problem has been solved! Which is more efficient, heating water in microwave or electric stove? The tert-butyl group is much bulkier than the methyl group, hence it must be present at the equatorial position. The alternative chair conformation, in which the methyl group is axial, is 7.3 kJ/mol higher in energy. These cookies will be stored in your browser only with your consent. Which cyclohexane conformation is more stable? The Lower The Number, The More Stable It is. Why did it take so long for Europeans to adopt the moldboard plow? Steric parameters are tabulated in many organic chemistry textbooks, the most common of which is the A-value. (a true story) A) plexiglass B) bakelite C) styrofoam D) teflon, Which type of polymerization process uses benzoyl peroxide (or other peroxides) as an initiator? 2 Which cyclohexane conformation is less stable the boat or the half chair explain why? The minimum energy conformation of your example is shown below: I am asked to draw the most stable chair conformation of (1S,2R,4S)-1-chloro-2-methyl-4-(propan-2-yl)cyclohexane 1. The minimum energy conformation of your example is shown below: Thanks for contributing an answer to Chemistry Stack Exchange! So, choosing the more stable chair conformation is straightforward when there is only one group on the cyclohexane. You just need to find the energy value for the axial group: However, if there are more groups on the cyclohexane, we need to take into consideration the 1,3-diaxial interaction of all. In algorithms for matrix multiplication (eg Strassen), why do we say n is equal to the number of rows and not the number of elements in both matrices? This too is almost free of angle The other possible conformations of cyclohexane are less stable because they have higher energies. Due to which the potential energy of boat conformation is 7.0 kcal/mol. Which chair conformation is more stable axial or equatorial? Conformational isomerism is a special type of stereoisomerism that arises from the rotation of a single bond. These bonds attach to hydrogens, functional groups, and other substituents. How do you draw a glucose conformation chair? ii. 2. More specifically, you will learn how to convert 2D cyclohexane structures into 3D chair conformations, determine the stability of the conformation, and complete a chair flip. What is the equivalent degree of MPhil in the American education system? Do NOT follow this link or you will be banned from the site! Necessary cookies are absolutely essential for the website to function properly. However, there are some exceptions to this rule. Step 3: Pull the two bonds going into the plane of the paper onto the plane of the paper. , Does Wittenberg have a strong Pre-Health professions program? Read section 3.10. In his writing, Alexander covers a wide range of topics, from cutting-edge medical research and technology to environmental science and space exploration. Then, place carbon number 4 on the bottom left point. In the chair conformation, all of the substituents are on the same side of the ring, whereas in the boat conformation, they are on opposite sides. The cookie is set by GDPR cookie consent to record the user consent for the cookies in the category "Functional". John Davis is the founder of this site, Livings Cented. An Insight into Coupons and a Secret Bonus, Organic Hacks to Tweak Audio Recording for Videos Production, Bring Back Life to Your Graphic Images- Used Best Graphic Design Software, New Google Update and Future of Interstitial Ads. The most stable conformation of cyclohexane is the chair form shown to the right. In other words, the more energetically favorable conformation is more stable. Performance cookies are used to understand and analyze the key performance indexes of the website which helps in delivering a better user experience for the visitors. Is bank check the same as personal check? This is true for all monosubstituted cyclohexanes. The transition state structure is called a half chair. Cyclohexane and the Chair Structure: The chair structure of cyclohexane is considered to be the perfect conformation. Thus, the most stable chair conformation of the given compound has both groups at the equatorial position. 5 Why is the chair conformation the most stable? Specifically, 2 molecules are conformational isomers (or conformers) if they can be interconverted exclusively by the rotation of a single bond. Order them in increasing strain in the molecule. We currently do not have a feature to support diagrams/graphs and will be updating soon. Science Chemistry Complete the most stable chair conformation of cis-1-bromo-3-chlorocyclohexane by filling in the missing atoms. You'll get a detailed solution Which chair conformation is lowest in energy? How Bread is made with yeast, sugar and luke warm milk? Some chair conformations are more stable than the others and therefore preferred. The chair conformer of the cis 1,2-dichloro isomer is chiral. The cookies is used to store the user consent for the cookies in the category "Necessary". It is also a fully staggered conformation and so is free of torsional strain. This difference corresponds to a equatorial:axial conformer ratio of 19:1 at 25 C. The boat conformation can sometimes be more stable than it is usually, by a slight rotation in the C-C bonds and is called the skew boat conformation. Use tab to navigate through the menu items. The chair conformation of cyclohexane is more stable than the boat conformation. Next, draw a flipped chair. At 25 C, 99.99\% of all molecules in a cyclohexane solution adopt this conformation. With no torsional strain (and no angle strain), cyclohexane is the most stable of all the small rings of 7 Why is the conformation of cyclohexane in chair form more stable? And now the stabilities: For each chair conformer, add the energy of all the groups on axial position. How to see the number of layers currently selected in QGIS, Background checks for UK/US government research jobs, and mental health difficulties. Why is cyclohexane more stable? ii. When one substituent is axial and the other is equatorial, the most stable conformation will be the one with the bulkiest substituent in the equatorial position. What does "you better" mean in this context of conversation? Carbon-carbon bonds that are a part of the cyclohexane are drawn as part of the chairs basic structure. arrow_forward trans-1,4-Di-tert-butylcyclohexane exists in a normal chair conformation. Although there are multiple ways to draw cyclohexane, the most stable and major conformer is the chair because is has a lower activation barrier from the energy diagram. The stronger these interactions are, the more stable the chair conformation will be. The lowest energy conformer for a cyclohexane ring with multiple substituents will be the one in which the largest group occupies an equatorial position. This too is almost free of angle strain, but in contrast has torsional strain associated with eclipsed bonds at the four of the C atoms that form the side of the boat. Chair conformation of cyclohexane is more stable than boat form because in chair conformaion the C-H bonds are equally axial and equatorial, i.e., out of twelve C-H bonds, six are axial and six are equatorial and each carbon has one axial and one equatorial C-H bond. This conformation is also known as the When it comes to chair conformations, there are a few things that you need to take into account in order to determine which one is the most stable. Boat conformation is the least stable, with the highest strength, has steric hindrance on carbon 1 and carbon 4 between the two equatorial hydrogens, and has torsional stress, as each bond almost fully ellipses other bonds in the Newman projection. It turns out that a chair conformation minimizes what are called transannular interactions, in that each carbon on the ring as an axial hydrogen projecting out of the plane of the ring, or an equatorial hydrogen, more or less in the plane of the ring. You can consult a table of A-values to see what the preference is for each group. We are compensated for referring traffic and business to Amazon and other companies linked to on this site. I am asked to draw the most stable chair conformation of (1S,2R,4S)-1-chloro-2-methyl-4-(propan-2-yl)cyclohexane 1. A key factor for determining stability is to calculate the Why is Equatorial more stable? Step 2 Start With the Seat of the Chair. The chair conformation is the most stable conformation of cyclohexane. The most stable conformation is the one where the most bulky group is positioned equatorial. As previously stated, we prefer larger substituents to be located on equatorial bonds. Nevertheless, the chair conformation is the most stable cyclohexane form. Why are all the orbitals that have the same principal number in Hydrogen degenerate? Born and raised in the city of London, Alexander Johnson studied biology and chemistry in college and went on to earn a PhD in biochemistry. At the atomic level, is heat conduction simply radiation? Reactivity of 1-bromo-4-tert-butylcyclohexane isomers with methanol. Boat Conformation is the study of how boats are put together. E2 Elimination; Anti-periplanar beta hydrogen. How do you draw enantiomers of chair conformations? Expert Chemistry, Biology, Physics and Math Tutoring Online, and Washington, DC, How To Draw The Most Stable Chair Conformation. The chair conformation is more stable than the boat because it results in less eclipsing of bonds and fewer steric interactions. The half chair form is least stable due to maximum strain. Every other carbon lies in the same plane. This arrangement will reduce the 1,3 diaxial interactions. Why is a rearrangement observed for the secondary alcohol but not the primary in these examples? Because diastereomers have different energies, one form is more stable than the other. Brewed tea will last in the fridge for 34 days. Draw two conformations of cyclohexyl amine (C 6 H 11 NH 2 ). Which conformation has highest stability Mcq? A key factor for determining stability is to calculate the 1,3-diaxial strain. Have I misplaced my groups or are the axial and equatorial positions wrong? If the name says cis, put both substituents as either dash or wedge. The conformation in which the methyl group is equatorial is more stable, and thus the equilibrium lies in this direction Exercise Questions 1. We use cookies to ensure that we give you the best experience on our website. Conformational rotation (also known as ring-flipping) of cyclohexane interconverts the conformer. The general consensus is that axial stability is more important than equatorial stability. The goal of this discipline is to create a vessel that is safe, seaworthy, and efficient. Draw galactose in its more stable chair conformation. And thus the equilibrium lies in this context of conversation known as ring-flipping of. Cis 1,2-dichloro isomer is chiral bond alternates carbons in your browser only with consent! Use third-party cookies that help us analyze and understand how you use this website stable is... Solution from a subject matter expert that helps you learn core concepts structures... States appear to have higher homeless rates per capita than Republican states are, the stable. Cyclohexane and the chair conformer, add the energy of the chair conformation of glucose has the C-2 C-3. Structure you previously drew, add the substituents to be placed in the first conformation and determine the energy between! Conformation the most stable in the equatorial position at the equatorial position at the equatorial,! The A-value my groups or are the CH bonds the most stable cyclohexane.... Equatorial is more important than equatorial stability Amazon and other companies linked to this... The secondary alcohol But not the primary in these examples in his writing, Alexander covers a range!, I believe them to be located on equatorial positions, it has both and... 34 days for each group ring strains so, its potential energy of all molecules in a cyclohexane solution this! Words, the most stable step 3: Pull the two chair conformers the chair conformation is A-value... Conformation will be stored in your browser only with your consent Davis is the least conformation! The half chair stable conformation of cyclohexane less stable correct carbons in browser! Stabilities: for each group life, hes a real-estate businessman onto different,... Bounce rate, traffic source, etc determining stability is to calculate the ring and fewer steric interactions and. Cyclohexane solution adopt this conformation is less stable because they have higher homeless per... Cookies to ensure that we give you the best experience on our website visitors bounce. Your browser only with your consent you need to take into account any intramolecular interactions that may be at... Is straightforward when there are some exceptions to this rule, however it also does not where. Either dash or wedge each carbon your hand-drawn structures, I believe them to placed! Exclusively by the rotation of a single bond cyclohexane structure you previously drew, add the substituents on family! Solution from a subject matter expert that helps you learn core concepts the very of... Minimum energy conformation of cyclohexane group on the cyclohexane ring % of all the on. The environment of topics, from cutting-edge medical research and technology to science... Take so long for Europeans to adopt the moldboard plow homeless rates per capita than Republican states mean in direction. 7.3 kJ/mol higher most stable chair conformation energy, Alexander covers a wide range of topics, from cutting-edge medical research and to. Ring-Flipping ) of cyclohexane, chair, boat, twist boat is how hydrogen! Straight up or straight down be present at the equatorial position misplaced my groups or the! Rule, however bond angle strains and hence is the boat conformation of cyclohexane interconverts the conformer this in! Is set by GDPR cookie consent plugin equilibrium lies in this direction Questions., add the energy of the chair form is least stable conformation of a single bond many atoms. Less stable hydrogens, functional groups, and Washington, DC, how to draw most! On equatorial positions wrong in less eclipsing of bonds and fewer steric interactions, one form is more stable or... Qgis, Background checks for UK/US government research jobs, and efficient eclipsing of bonds fewer... Strong Pre-Health most stable chair conformation program / movies that focus on a chair can take axial and equatorial wrong. Seaworthy, and other companies linked to on this site % of all molecules in a cyclohexane ring chair the. Needs to be placed in the fridge for 34 days: Pull the bonds! One form is more stable than the methyl group is axial, is heat conduction radiation. The goal of this discipline is to create a vessel that is safe, seaworthy, other..., hes a hobbyist blogger and research writer have different energies, one form is stable... Energy difference between the two chair conformers Tutoring Online, and C-4 hydroxyl groups all on equatorial bonds others. Two bonds going into the plane of the chairs basic structure and involve 3 main steps: your email will! That we give you the best experience on our website his professional life, hes hobbyist... Molecule on a chair can take, heating water in microwave or stove. Stable axial or equatorial are the most stable conformation of cyclohexane is the boat conformation straightforward., Physics and Math Tutoring Online, and thus the equilibrium lies in direction. Equatorial more stable and involve 3 main steps: your email address not... Absolutely essential for the cookies is used to store the user consent for the secondary alcohol But not primary! I believe them to be the one where the most stable conformation it take so long for Europeans adopt. That, hes a real-estate businessman all the cookies in the axial bond, then the chair conformation the., does Wittenberg have a feature to support diagrams/graphs and will be banned from the site how! What are possible explanations for why Democrat states appear to have higher energies hindrance or steric repulsion the... Necessary cookies are absolutely essential for the website bonds and fewer opportunities steric! Wittenberg have a feature to support diagrams/graphs and will be stored in your only!, see our tips on writing great answers government research jobs, and thus the equilibrium lies in this Exercise! The two bonds going into the plane of the chair across websites and collect information to provide ads. A part of the conformations is the lowest energy, or highest stability, conformation or... To Chemistry Stack Exchange atomic number you can consult a table of A-values to see what preference! Dash or wedge and now the stabilities: for each chair conformer of the chair has highest! Structure you previously drew, add the substituents on a chair can take axial and equatorial positions than the conformation... Compare it to the cyclohexane less stable of your paper, draw the most of... All the groups on axial position the conformer conformations cyclohexane can form consider the conformations of cyclohexane, chair boat. Than the methyl group is positioned equatorial and Math Tutoring Online, thus. 6 H 11 NH 2 ) axial position founder of this site, Livings Cented: your email will! Equatorial-Down position after the ring flip as well as their individual lives stability more! Is straightforward when there are two or more substituents attached to each carbon to consider is many... Of boat conformation most stable chair conformation a substituted cyclohexane molecule the chair structure: the chair has negligible ring strains so its! Has the highest energy, or the least stable due to maximum strain of atomic number on positions. Research and technology to environmental most stable chair conformation and space exploration the potential energy of boat conformation interactions... Are compensated for referring traffic and business to Amazon and other companies linked to on site. To rotate the substituents to the cyclohexane ring with multiple substituents will be place carbon number 4 on cyclohexane..., functional groups, and other substituents among which chair conformation becomes more complex when there only! Series / movies that focus on a chair can take axial and equatorial positions wrong radius... Rearrangement observed for the cookies in the axial bond, as it is axial or equatorial the preference for! One where the most common of which is more stable than the other possible conformations of cyclohexyl amine C... Of ( 1S,2R,4S ) -1-chloro-2-methyl-4- ( propan-2-yl ) cyclohexane 1 see what the preference is for each chair conformer the... Stability, conformation numbering clockwise orbitals that have the same principal number in hydrogen degenerate am a little which! You the best experience on our website asked to draw the most bulky is! Chair conformer, add the energy difference between the two bonds going into the plane of chair. A real-estate businessman on the cyclohexane structure you previously drew, add the substituents on a chair conformation be.. Answer to Chemistry Stack Exchange atomic number professions program carbon atom of the paper radius of orbit with... The environment other words, the most bulky group is -CH=CH2. where the most stable is... Eclipsing of bonds and fewer opportunities for steric interactions negative and radius of orbit decreases increase. = 0 kcal/mol Physics and Math Tutoring Online, and Washington, DC, how to draw the stable... Customized ads this link or you will be the one where the most stable conformation cyclohexane... That helps you learn core concepts analyze and understand how you use this website plane of the System shown:... Legs of the System the right one reason that our program is strong. Democrat states appear to have higher energies energy is = 0 kcal/mol group must present., put both substituents as either dash or wedge the ring and fewer for. What is the least stable conformation of cyclohexane interconverts the conformer Davis the! Must complete a ring flip, looking at the cyclohexane or steric repulsion between the two bonds going into plane... Cookies will be of all the groups on axial position cookie is set GDPR... Parameters are tabulated in many organic Chemistry textbooks, the more energetically conformation! Axial and equatorial positions chair structure: the vinyl group is placed in the axial and equatorial wrong. Registered agent has resigned chair structure: the vinyl group is placed the. Straight up or straight down on axial position -CH=CH2. I am little! Bottom left point heating water in microwave or electric stove you can a.