Extremely efficient chiral induction in conjugate additions of p-tolyl alpha-lithio-beta-(trimethylsilyl)ethyl sulfoxide and subsequent electrophilictrapping reactions

Reaction of p-tolyl alpha-lithio-beta-(trimethylsilyl)ethyl sulfoxide with alpha,beta-unsaturated esters gave the conjugate addition products as a sin gle diastereomer. The intermediate enolates were subsequently trapped with various alkyl halides or aldehydes to give the products with extremely high stereoselectivity. The reaction with alpha,beta-unsaturated ketones also p roceeded with high diastereo-selectivity. Protolysis of the enolates derive d from the alpha-methyl-alpha,beta-unsaturated esters gave the products wit h high stereoselectivity. The stereo- and regioselective elimination of the sulfinyl group gave chiral homoallylic carboxylates.