Chair conformers of cyclohexane

Question 1

what happens to atoms in axial and equitorial when flipped?

Answer 1

axial = equatorial and equatorial = axial but “up” remains “up” and “down” remains down

Question 2

if a cyclohexane has two substituents is having them in equilateral or axial positions more favourable? Why or why not? Are there exceptions to this rule?

Answer 2

2 groups in equilateral position mostly favoured and 2 groups in axial least favoured. if both groups are in axial positions, they are much more closer to each other and therefore more likely to repel from each other which further destabilises the molecule. Exceptions if both groups are BULKY (di-t-butyl) and are right next to each other (C1 and C2). Having groups in axial and equitoail will further part the molecules decreasing the 1,2 strain

Question 3

decalin is two cyclohexane fused together. Is the trans or cis version more stable?

Answer 3

transdecalin where the C-C bond of the two cyclcohexanes at the bridge head are trans is more stable than cis version. Trans has both C-C bonds in equatorial position reducing gauche + further stabilising the molecule

Question 4

Can the trans conformer of decalin be ring flipped? Draw It out and decide why or why not

Answer 4

It cannot be flipped as it is locked in position as flipping it would cause too much ring strain