Question

explain why t butyl group in t butyl cyclohexane is locked at equatorial position​

Answer 1

Answer:

tert-Butyl groups "lock" cyclohexanes into a conformation where the tert-butyl group occupies an equatorial position and the ring-flip equilibrium is essentially stopped. To verify this fact, write the ring-flip equilibrium of cis-1-tert-butyl-4-methylcyclohexane such that the least stable chair conformation is the product (this will cause the ΔE to be greater than (or equal to) zero.

T = 298 K

R = 8.315 J/mole-K

H - Substituent Interaction 1,3-Diaxial Strain (kJ/mole)

H ←→ CH3 = 3.8

H ←→ C(CH3)3 = 11.4