To assess the stereospecificity of our approach as well as its applicability on a larger scale, we synthesized gram quantities of enantiopure β-lactam 6j in three steps starting from methyl phenyl sulfone (Scheme 6). Using method B and commercially available (R)propylene oxide (see Scheme 3), chiral sulfonylcyclopropane 4f was obtained in reasonable yield and subjected to our αhydroxylation procedure, furnishing enantiopure cyclopropanone equivalent 5f in 80% isolated yield. Gratifyingly, directly submitting this chiral 1-sulfonylcyclopropanol to our formal [3+1] cycloaddition conditions afforded 1.25 gram of chiral β-lactam 6j in 88% yield and >99% ee, ultimately confirming the stereospecific nature of the 1,2-shift occurring during the ring expansion. Scheme 6. Asymmetric gram-scale synthesis of chiral cyclopropanone equivalent 5f and β-lactam 6j