Question

Devise the most efficient synthesis for the carboxylic acid below using a starting material and reagents from the tables. Give your route by specifying the number of the starting material followed by the letters of the reagents you would use beginning with the first step.
The answer 4fh means treat t-butanol(4) with conc. HCl(f) then treat the product with KOH in alcohol(h).

OH OH Starting materials Br Br OH OH Reagents Aqueous H,SO, at rofu f Conc. HCI or HCI (gas) g PBr a Mg /dry ether e Aqueous H2SO, at reflux b1.Co2 2. acidic workup Na2 CrOs/aqueous H SO4 c NaCN/THF or DMF d NaCN/dil. aqueous HSO h KOH/alcohol The most efficient synthetic route is

Answer 1

answer LCN h Macw/HForbut, m en NACNAHF orDMF 0 ack TH CNO In solvent e.g. THE, DMF & CN aprotic polar polar aprotic OH as a strong nucleophile. e n @ 49- Hysog at reflux EN Protonation - CN group of alkoxy group and hydrolysis of occurs at refluxing condition in acidic medium. most efficient synthetic route : 50e