Question

Using 2-propanol, or rubbing alcohol, as your only starting material, draw a path of synthesis (with structures, reagents, and solvents) that would deliver 2,3-dimethyl-butan-2-ol using Grignard reagent.

Answer 1

Propan-2-ol converted to 2-Chloropropane using Lucas reagent (ZnCl2/HCl). 2-Chloropropane then treated with pure polished Mg metal pieces in Diethylether solvent which gives a Grignard Reagent G.R.

Propan-2-ol oxidized to Propan-2-one using pyridiniumchlorochromate (in dichloromethane solvent) - a selective and less reactive oxidizing agent.

Propan-2-one and G.R. allowed to react in ether solvent. The Mg complex formed on acid hydrolysis gives the product 2, 3-Dimethylbutan-2-ol.

Hence the synthesis.