Asymmetric synthesis of (+)-citrinin using an ortho-toluate carbanion generated by a chiral base

The carbanion (3), generated using the chiral lithium amide base (1), undergoes enantioselective addition to acetaldehyde and acetone with a high degree of asymmetric induction at the nucleophilic centre; the reaction with acetaldehyde is exploited in an enantioselective synthesis of (+)-citrin (10).