and 30% in acetonitrile respectively. After purification, one product 6a is confirmed as 1R,2R by ORTEP. The less reactivity of the camphorsultam toward cyclopropanation may be due to the electrostatic repulsion between the sulfone functionality in the chiral auxiliary with the nucleophilic sulfur ylide . The beta phenyl substrate, 2b gives exclusive 7a and 7b in toluene and acetonitrile, respectively. Newly formed stereogenic centers in 7b are confirmed by ORTEP as 1S,2R,3R. where the ethyl ester group is in cis orientation with chiral amide bond. In case of sultam substrate 2m gives same product 8b in toluene and acetonitrile in 25 and 23% yield, respectively. The ORTEP confirmed 8b absolute configurations as IR,2R,3R, where ethyl ester group is trans to chiral auxiliary amide.