Questions tagged [cyclohexane]
Cyclohexane is a cycloalkane with the molecular formula $\ce{C6H12}$. This tag should be applied to questions about the properties and reactions of cyclohexane and its derivatives.
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Why the C4 in this 1,3,4,5-substituted Cyclohexanes has a R/S configuration?
(1S,3S,4S,5S)-3,5-dimethoxy-1-phenylcyclohexane-1,4-dithiol.
ChemDraw21 shows the C4 is S configuration. However I think C4 has two same function groups(C3 and C5 are both S configuration; C2-1-6 and ...
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Calculating energy difference between two 1-4 dimethylcyclohexane conformers
The following question was asked in a quiz at my college
Draw the most stable and least stable chair conformer for 1,4-dimethylcyclohexane and calculate the
energy difference between these two. Given ...
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Can we always use the planar representation of cycloalkanes instead of their true conformations to study their stereochemistry and chirality?
When I have drawn stereoisomers of substituted cyclohexanes and checked if they are chiral, I typically represent the ring as a planar hexagon and look for symmetry elements. For example, I would use ...
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Threshold of steric hindrance for the axial position in cyclohexanes
My professor mentioned that isopropyl is able to go into the axial position on the chair conformation of a cyclohexane, while tert-butyl cannot. This made me wonder then, at what point is a ...
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Are substituents placed alphabetically in the name of a cycloalkane?
I named this molecule 1,5-diethyl-2-methyl-4-propylcyclohexane. Is this correct? Or should we somehow use the size of the substituents?
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Why is diequatorial trans-1,2-dimethylcyclohexane more stable than diaxial trans-1,2-dimethylcyclohexane?
Consider diequatorial trans-1,2-dimethylcyclohexane and diaxial trans-1,2-dimethylcyclohexane as shown in the figure below [1, p. 178]. In both compounds, the ring is free of angle strain.
trans-1,2-...
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Why 5-member rings prefer being cis-fused?
It always bothers me how whenever I am doing practice problems I never got a proper explanation as to why 5-member rings prefer(thermodynamically) being cis- rather than trans-fused( as opposed to ...
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Number of stereoisomers of 1,3,5-trimethylcyclohexane
When I searched the stereoisomers of 1,3,5-trimethylcyclohexane, I got four structures given below.
I don't get how structures 1 and 2, 3, and 4 are not the same. Could anyone explain?
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Ring Flip of glucose
I have recently read about mutarotation of glucose specifically
I am familiar with how cyclic structures like substituted cyclo-hexanes exist in an equilibrium of both their chair conformers.
The ...
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Planarity at the Junction between multiple Rings
My Approach:
As cyclohexane should be in the chair form and cyclopentane should be in the envelope form, more the number of five-membered rings more should be its planarity, as envelope form is more ...
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Can exact bond angles in cycloalkanes be calculated?
I know that bond angles in cycloalkanes are usually different from $\ce{109.5}^{\circ}$ as predicted by the VSEPR theory because of their shape, and a higher deviation will cause a higher ring strain. ...
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Can acetaldehyde be condensed with methyl vinyl ketone to form 2-Cyclohexen-1-one as per the Robinson annulation
I have seen that cyclohexanone can react with methyl vinyl ketone to form a fused bicyclic cyclohexenone, I am wondering if the same reaction can be used to produce cyclohexenone the single ring ...
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Is it correct to look at plane of symmetry in substituted cyclohexane for determining a meso compound?
I read this question and it's answer by @orthocresol. Now, he has written that the compound in question is meso not because there is a plane of symmetry but because of the rapid flipping of the ...
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Is cyclohexane‐1,3‐dicarboxylic acid a correct IUPAC name?
I did the numbering by taking all the functional groups in principal chain (scheme A), but my teacher did it differently and proposed the name cyclohexane‐1,3‐dicarboxylic acid (scheme B):
The ...
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Why can't cyclohexylbenzene be called benzylcyclohexane? [closed]
The following structure represents the compound cyclohexylbenzene:
Why can't the benzene ring be treated as a substituent and the compound be called benzylcyclohexane?
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How to identify cis and trans forms of cyclohexane [closed]
How can identify which one is cis and which one is trans . If I consider it as a planar molecule (though it is not) I understand that if the substituents are in same side it is cis else trans but this ...
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Steric effect of t-butyl group on SN1 on a cyclohexane ring
This is a question from GRB Kota Question Bank Organic Chemistry, Chapter 3, Reasoning type, Q. 4:
Assertion: trans-1-t-butyl-4-chlorocyclohexane is less reactive than cis-1-t-butyl-4-...
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How many gauche butane interactions are present in cis-1,2-dimethylcyclohexane?
We were asked to find out the number of Gauche-Butane interactions for this compound:
I proceeded by drawing the Newman Projection for this chair conformation as follows and marked the Gauche-Butane ...
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Stability of cyclohexane type species
I came across a question where we have to find out the stability of species that are in chair conformations. The species are as follows:
Comparing the 'A' values tells me that compound I, III and VI ...
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Optical activity in cyclohexane [duplicate]
In case of checking for the optical activity of cyclohexane or its derivative why we check for POS and COS in its cyclic 6 membered planar eclipsed state but not by its real conformation it forms ...
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Can a substituted cyclohexane progress through SN1?
I have read that when the leaving group substituent is stuck in the equatorial position for some reason (like from a t-butyl group or a trans decalin), SN2 is either very slow or just doesn't happen ...
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Strains in conformations of cyclohexane
I know some the basic kind of strains that can exist in molecules namely Torsional strain (Vanderwaals' strain), steric strain and angle strain.
Is it possible to associate a particular type of ...
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Why bridged bicyclic compound isn't a preferred product over fused bicylic compound in Robinson Annulation reaction?
Why a doubly-fused cyclohexanone is formed instead of bridged cyclohexanone like product which would be more flexible (entropically-favoured)?
Also, the OH group not being at the bridgehead carbon ...
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Why was Nobel Prize given to Baeyer for his "faulty" Baeyer's Strain Theory? [closed]
Baeyer Strain Theory said that using the formula
$\frac{(109^ \circ 28' - \alpha)}{2}$, where $\alpha$ is the angle between 2 sides of the cycloalkane, the most stable cycloalkane could be found. ...
user92006
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Can a boat conformer of cyclohexane be most stable?
It is well-known that the "chair" conformation of cyclohexane is the most stable of its conformers. But is there any cyclohexane derivative where other notable conformers (boat, half-chair) are the ...
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Is boat form of cyclohexane non polar?
In chair form of cyclohexane the C-H dipole moments cancel out each other but in boat form i don't think all dipole moments will be cancelled out. Also if boat form is polar then what will we say ...
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Heat of hydrogenation of 1,3-substituted cyclohexanes
From these two molecules in question, (C) should be more unstable as it is in a cis-configuration. The t-butyl and methyl groups being on the same side of the ring would exert a larger steric force on ...
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Is there a gauche interaction between C-3 and C-6 in cyclohexane?
To my understanding, a gauche interaction occurs between two R groups when staggered by 60 degrees in a Newman Projection. When looking down the C-1 to C-2 bond of a cyclohexane, the Newman Projection ...
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Cyclohexane derivative formation of carambolaflavone using a Lewis acid catalyst
The scheme below summarizes the results from a study into the optimum conditions needed for a key step in the synthesis of the proposed structure of carambolaflavone, a natural product that has ...
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Stability of Cycloalkyl Carbocations
What is the order of stability of the cycloalkyl carbocations?
I think the stability should increase as we move from cyclopropyl carbocation to cyclohexyl carbocation, since the angle strain is ...
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Chugaev and Selenoxide Elimination giving different products
In class we are going over intramolecular elimination. In this question I will provide two similar reactants that provide a different mixture of products.
The chugaev elimination gives a 50/50 ...
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Is cyclohexane saturated or unsaturated?
I have this confusion that cyclohexane is of form $\ce{C_{n}H_{2n}}$ and so it must be an unsaturated compound, but also it does not have a double or triple bond so it must be saturated.
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Most stable chair conformation
I am asked to draw the most stable chair conformation of (1S,2R,4S)-1-chloro-2-methyl-4-(propan-2-yl)cyclohexane 1.
After doing so I am a little uncertain which of the conformations is the most ...
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Why does 1,2-dimethylcyclohexane only possess three stereoisomers? [duplicate]
Why does 1,2-dimethylcyclohexane in chair form have only three stereoisomers?
I understand that the trans isomer doesn't possess plane of symmetry and thus it has two stereoisomers. But my book says ...
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Why does 1,3-dimethylcyclopent-1-ene have geometric isomerism while 1-bromo-2-chlorobenzene doesn't?
The bottom compound has bromine and an R group connected to one of its SP2 double bond carbons, and chlorine and the same R group connected to the other. This fact, it would seem, indicates cis-trans ...
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Synthesis of methylenecyclohexane from cyclohexylmethanol
I want to form methylenecyclohexane from cyclohexylmethanol
I'm thinking about an $\mathrm{E1cB}$ mechanism since the β-hydrogens will be quite acidic (similar electronegativity to fluorine). ...
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What would this unsaturated cyclic compound be called?
I came across this compound recently, and havent been able to find out what it's name could possibly be:
My guess was maybe it's "cyclohexylene cyclohexane", but not quite sure. Can anyone tell me ...
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Cyclohexene reduction reaction with hydrogen gas and ethanol [closed]
I have a following reaction (see below). I found the section of reduction and oxidation states in my book but there is nothing about cyclohexenes. I know that the double bond will be reduced in this ...
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Help with absolute configuration of a substituted cyclohexane?
How is the absolute configuration decided when it is a cyclohexane and several stereocenters? Up to now we have only worked with simple molecules which are only 1. I believe the stereocenters here are ...
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Most stable conformational isomer of 3-methoxycyclohexan-1-ol
Among the following, the most stable isomer is?
I am aware of the fact that equatorial substituents are more stable than axial substituents but couldn't proceed to apply it here. However the answer ...
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How to determine the stereochemistry after elimination of anti-1-bromo-2-methylcyclohexane?
The question is asking for the product and the answer is C.
My expected answer was E. Here's how I tried to solve it:
Since Br (the leaving group) is at the equatorial position, the structure would '...
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Best chair configuration for trimethylcyclohexane matching a specific Haworth projection?
Which option best depicts trimethylcyclohexane shown in the Haworth projection below?
I thought B because
All the methyl groups are equatorial and equatorial groups are more stable.
All the methyl ...
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Is cis-1,2-dimethylcyclohexane a meso compound?
I was watching a video lecture today on hydrocarbons and came across this. The instructor says that, as there is a plane of symmetry, cis-1,2-dimethylcyclohexane is a meso-compound:
However, the ...
user14857
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Is the SN1 reaction faster with an axial or equatorial leaving group?
Why does compound 1 undergo the $\mathrm{S_N1}$ reaction faster than 2 even though both proceed via the same carbocation intermediate?
user14857
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Can wedge and dash bonds on 1, 2 position of cyclohexane ring be used to signify trans orientation of the substituents?
I've to make the structural isomers for cyclohexane. On position 1, there's a methane group with wedge bond and on position 2, a methane with dash bond. So I'll have to make the trans isomers only as ...
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Diastereoselectivity in synthesis problem (4 stereocenters)
Why is the particular diastereomer the major product of the sequence starting from racemic enone? I know that hydroboration is syn, therefore the arrangement of ring junction H atom and OH group. Why ...
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Decarboxylation / Elimination type reaction
I'm quite familiar with E1/E2 reactions and usually use those ideas to explain elimination reactions, however I came across a reaction which was a bit different (in the sense it isn't E1/E2) but still ...
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What are all the stereoisomers of 1-ethyl-3-methylcyclohexane?
What are all the stereoisomers of 1-ethyl-3-methylcyclohexane? The following image shows my attempt to answer the question. But I am not sure if I am correct.
Note: I am treating this cyclohexane as ...
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Boiling/melting points of cyclohexane and cycloheptane
I’m looking at a chart in my book, and while cycloheptane has a higher boiling point than cyclohexane like I’d expect, cycloheptane has a melting point of −12 °C, while cyclohexane has a melting point ...
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