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 does there need to be a planar intermediate in 2,2'-dibromobiphenyl when one of the phenyl groups rotates?

I was in class and my professor brought up the example of 2,2'-dibromobiphenyl: In her example, one of the bromines was actually pointing into the page and the two phenyl groups were not actually on ...
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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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Why do 6 member rings have lower strain than 5 member rings? [duplicate]

I was having a look at this graph here graphing the ring strains for various chain lengths: Evidently, 6 member rings have lower strain energy than 5 member rings. However, looking at the bond angles ...
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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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1answer
42 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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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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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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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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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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2answers
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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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1answer
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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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1answer
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Stereochemistry of 1,4 disubstituted cyclohexane [closed]

How are these cyclohexanes identical?
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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 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 ...
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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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820 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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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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679 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
769 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 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 ...
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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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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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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 ...
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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 ...
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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 ...
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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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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 ...
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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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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, ...
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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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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? ...
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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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Equivalent Cyclohexane Structures?

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