Asymmetric Dihydroxylations of β‐Substituted N‐(α,β‐Enoyl)bornane‐10,2‐sultams

Pure ( E )‐ or ( Z )‐enoylsultams 2 were Oxidized with OsO 4 / N ‐Methylmorpholine N ‐oxide in a stereospecific and highly π‐face‐selective manner. Acetalization of the resulting 1,2‐diols furnished, after purification, the stable, crystalline acetals 6 in >99% d.e. and in 63–74% overall yield from 2 . Reductive or hydrolytic cleavage of 6 gave enantiomerically pure alcohols 8 or carboxylic acids 9 with recovery of the sultan auxiliary 1 .