ASYMMETRIC CONJUGATE ADDITIONS OF CHIRAL ALLYLPHOSPHONAMIDE AND CROTYLPHOSPHONAMIDE ANIONS TO ALPHA,BETA-UNSATURATED CARBONYL-COMPOUNDS - HIGHLY STEREOCONTROLLED ACCESS TO VICINALLY SUBSTITUTED CARBON CENTERS AND CHEMICALLY ASYMMETRIZED CHIRONS

Reactions of anions derived from chiral nonracemic allyl and crotyl bi cyclic phosphonamides with alpha,beta-unsaturated cyclic ketones, este rs, lactones, and lactams take place at the gamma-position of the reag ents and lead to diastereomerically pure or highly enriched products o f conjugate addition. The option to quench the corresponding enolates with various alkyl halides offers a versatile approach to vicinal subs titution including the generation of quaternary carbon centers.