Enantioselective Protonation of a Simple Enol: Aminoalcohol‐Catalyzed Ketonization of a Photochemically Produced 2‐Methylinden‐3‐ol

Abstract

The enol 2, produced by a Norrish type II photoelimination from 1, is protonated enantioselectively to ketone 3 in the presence of (–)-ephedrine. Best optical yields are obtained at 0oC using small amounts of the chiral aminoalcohol. There is still wide scope for optimization.