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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18
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2answers
13k views

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 ...
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2answers
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Effect of periodic acid on cyclohexane derivatives

Periodic acid (per-iodic acid, $\ce{HIO4}$ ) cleaves vicinal diols(to carbonyls) via a cyclic intermediate. Due to the cyclic intermediate, it needs a syn configuration for the $\ce{-OH}$ groups for ...
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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 ...
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1answer
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Conformations of Cyclohexane

Is there any such thing as a twist chair conformation? Also, the boat and the chair conformations are achiral, while the twist boat conformation of cyclohexane is chiral and dissymetric. What about ...
9
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1answer
263 views

Why is it that the bigger the side-chain is, its hydrogen atoms tend to be more equatorial?

The most stable cyclohexane form is the chair conformation but on the other hand, the bigger the side-chain of the cyclohexane is, its hydrogen atoms become more equatorial rather than axial, which ...
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1answer
885 views

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 ...
6
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3answers
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Which cyclohexane conformation is more stable?

I got this question wrong on a test and I don't know why: Question: Which conformation is more stable? Answer: the chair on the left is more stable. I thought that the ring conformation ...
6
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3answers
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E2 Elimination; Anti-periplanar beta hydrogen

I'm confused by this picture I found on masterorganicchemistry.com—a very popular organic chemistry website: I agree that the product is a product. However, can't there be another product? ...
6
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1answer
105 views

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 ...
6
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1answer
302 views

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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3answers
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Boat conformation: axial hydrogens

In my exam, my teacher asked me if the following is true: "The chair cyclohexane has more axial hydrogens" I did not have time to think, so I just put false. And apparently I was right. But, at home, ...
5
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1answer
123 views

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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1answer
778 views

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). ...
5
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1answer
375 views

How to calculate the frequency of cyclohexane conformational interconversion?

My book mentioned that the energy barrier for cyclohexane to reach the half-chair conformation is $50.6\ \mathrm{kJ\ mol^{-1}}$. It says that from this value, it was calculated that cyclohexane ...
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3answers
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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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1answer
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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?
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1answer
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Most stable chair conformation

I am asked to draw the most stable chair conformation of compound 1. After doing so I am a little uncertain which of the conformations is the most stable. The most stable conformation is the one ...
3
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1answer
2k views

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 ...
3
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1answer
11k views

Understanding the hybridization of cyclohexane?

I'm having quite a fair bit of trouble comprehending the hybridization of cyclohexane. I understand that this is a ringed structure with single C-C bonds, therefore all the carbons should have sp3 ...
3
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2answers
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What are the bond angles in cyclohexane?

In the chair conformation of cyclohexane, what are the angles of the triangles defined by: a carbon atom, an axial hydrogen bonded to it, and the midpoint of a vicinal C-C bond ? a carbon atom, an ...
3
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1answer
2k views

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 ...
3
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1answer
835 views

Strain Energy in di-axial vs di-equatorial

I am dealing with two conformations of cis-1,4-dimethylcyclohexane. One conformation is di-axial, and the other one is di-equatorial. Why does di-axial have higher strain energy. I would make sense if ...
3
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1answer
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What are the priorities for substituent groups on a cyclohexane?

I was wondering about this specific scenario: If you have a cyclohexane, for example, and the cyclohexane has two consecutive substituent groups, for example a methyl group and an ethyl group, how do ...
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1answer
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What are the triple point pressure and temperature for pure cyclohexane?

Here is a video that demonstrates the interesting nature of the triple point of cyclohexane, so I tried researching on the internet for a phase diagram, but only found data from a manufacture where ...
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0answers
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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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1answer
380 views

Stereochemistry of 1,4 disubstituted cyclohexane [closed]

How are these cyclohexanes identical?
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1answer
606 views

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 methyls are equatorial and equatorial groups are more stable. All the methyl ...
2
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2answers
129 views

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 ...
2
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1answer
41 views

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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1answer
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Solvation effect on cyclohexane

I ran molecular dynamics simulation with a molecule of methylcyclohexane soaked into a water box. On the other hand I ran Monte Carlo with the molecule alone (no soaking). I performed this for the ...
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2answers
364 views

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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1answer
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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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0answers
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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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2answers
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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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1answer
628 views

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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1answer
747 views

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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1answer
30 views

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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0answers
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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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1answer
83 views

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. ...
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1answer
451 views

How to solve 1-deuterio-3-methylcyclohexene dehydrohalogenation?

Ive been struggling to solve this dehydrohalogenataion excercise. How does the E2 mechanism work in this case and how is it affected by the stereoselectivity and antiperiplanar position? How do I get ...
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1answer
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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 ...
0
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1answer
413 views

Equivalent Cyclohexane Structures?

Are these structures equivalent? Image 1: http://i.minus.com/jnojtCx6wYvqD.png Image 2:
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1answer
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Double Newman Projections

How do I draw a double Newman projection for cyclohexane? Which bond(s) do I sight down? From what I understand, if we have 1-methylcyclohexane, we sight C1-C2 and C5-C4, as shown in my attempt ...
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0answers
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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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0answers
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Difference in the boiling point of piperidine and cyclohexanamine

The reason that I believe must be the difference in the amount of hydrogen bonding formed by both of the compounds in the liquid . But I suspected that both must be having same amount of hydrogen ...
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2answers
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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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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 ...