An asymmetric synthesis of the highly oxygenated cyclopentanoid antibiotic (+)- kjellmanianone (1) has been achieved. The key step entailed enantioselective hydroxylation of the prochiral sodium enolate of β-keto ester 2 with the new, enantiomerically pure N- sulfonyloxaziridine 7b, affording 1 in 68.5% ee (60% yield). Possible transition state structures for the asymmetric oxidation are evaluated.
