a. How many conformational isomers are possible of 4-isopropyl cylohexan-1,2-diols (I) ?
b. Which isomers of (I) cannot form intramolecular H-bonding ?
c. Which conformational isomer of cis-cyclohexan-1,3-diol forms intramolecular H-bonding ?
d. Which conformational isomer of cis-cyclohexan-1,4-diol forms intramonal H-bonding ?

Explanation

a. For conformational isomers are possible. Bulky isopropyl group in equatiorial (e) form is more stable


b. Isomer (A) cannot form H-bonding since two (OH) groups are position and point away form each other. Stability order is `B gt C = D gt A` . (Diequatorial form is more stable).
c.
Although (I) is diaxial, it is more than diequatorial (II) due to H-bonding in (I).
d. Diaxial boat form of cis-cyclohexan-1,4-diol forms H-bonding due to very close (1fp - 4fp) distance (183 pm) and thus is more stable.

Although (I) daixial, it is more stable than diequatorial (II) due to H-bonding in (I).