How many gauche interactions does 1/3-Dimethylcyclohexane have?
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While each axial methyl group has four gauche interactions (3.6 kcal/mol) (think of each axial methyl group as a component of axial methylcyclohexane), there is also an interaction between the substituent axial methyl groups.
Which chair conformation is the most stable conformation of cis-1/3-Dimethylcyclohexane?
Because large groups prefer to be equatorial, the most stable conformer for cis-1,3-dimethylcyclohexane is the diequatorial conformer, shown here. The diaxial conformer would be higher in energy.
What is a Diaxial interaction?
Diaxial interaction (1,3-diaxial interaction): An interaction (usually repulsive) between two axial substituents on a cyclohexane ring. On the top face of this chair cyclohexane, the axial methyl groups and axial hydrogen atom experience diaxial repulsion (indicated with the red dashed line).
How many gauche butane interactions does cis 1/2 Dimethylcyclohexane have?
The diaxial conformer is equivalent to two axial methylcyclohexanes…. one above the ring; one below. Thus there are four gauche butane interactions.
Why is it called 1/3 Diaxial interactions?
1,3-Diaxial interactions are steric interactions between an axial substituent located on carbon atom 1 of a cyclohexane ring and the hydrogen atoms (or other substituents) located on carbon atoms 3 and 5.
How can you tell if a Diaxial interaction is 1 3?
What is the energy cost of a 1/3 Diaxial interaction between a chlorine and a methyl group?
10,96 kJ/mol
Thus the energy cost of a1,3 diaxial interaction between a chlorine and a methyl group is 10,96 kJ/mol.
What are the possible chair conformations that are formed by 1 1 Dimethylcyclohexane?
1,1-dimethylcyclohexane does not have cis or trans isomers, because both methyl groups are on the same ring carbon. Both chair conformers have one methyl group in an axial position and one methyl group in an equatorial position giving both the same relative stability.
How do I know how many gauche interactions I have?
Another way to view gauche butane interactions is to count the number of axial methyl groups (or any other group for that matter) that bear a 1,3-relationship to axial hydrogens. The energy of the diaxial conformation is 4 x 0.9 or 2 x 1.8 = 3.6 kcal/mol.
How many gauche interaction are there in cis decline?
for cis-decalin (using cis-decalin 1 for the sake of discussion) clearly has 1,3-diaxial interactions (gauche butane interactions).