Highly diastereoselective alkylation of vicinal dianions of chiral succinic acid derivatives: a new general strategy to ( R)-β-arylmethyl-γ-butyrolactones

Abstract

The vicinal dianions derived from chiral succinic acid derivatives, 1,4-bis[(4 R,5 S)-3,4-dimethyl-2-oxo-5-phenylimidazolidin-1-yl]butane-1,4-dione and 1,4-bis[(4 S,5 R)-3,4-dimethyl-2-oxo-5-phenylimidazolidin-1-yl]butane-1,4-dione react with arylmethyl bromides with high diastereo- and regio-selectivity to provide the corresponding chiral α-arylmethylated succinic acid derivatives; the ( R)-products are converted into ( R)-β-arylmethyl-γ-butyrolactones and ( R)-α-arylmethyl-γ-butyrolactones.