Question

Draw the mechanism of the dehydration of 4-methylcyclohexanol with H3PO4 and list the major and minor product(s).

Answer 1

Mechanism of 4-methyl cycle herand with H3PO4 4-methyl cyclohexanol is a Secondary alcohol, this undergo dehydration through E elimination process in presence of H₂PO4 In First step alcohol gets protonated. Then H₂O molecule eliminates from the product by forming a Carbocation - finally, deprotonation takes place by H₂O to form alkene. Mechanism H, OH OH OK P-OH H2O tah H 1 CH₂ CH3 protonation G-methyl cyclohexanol I De protonation 3 4-methyl coelo benene Ethect of geometric isomerism: the starting material is a mixture of Gs, trans i somers. However, in E, elimination geometrical isomers have no effect For both as a trans isomers will form same carbocation in this reaction which undergo elimination. CH3 M H3PO4 H₂O i planar spre carbon .CHA MOH trans OH Сн; KH20.