Synthesis of (−)-Pinidine via asymmetric,electrophilic enolate hydroxyamination/nitrone reduction

Enantiomerically pure(?)-pinidine ( 1 ) has been synthesized in 18.5% overall yield by a nine-step sequence starting from keto-ester 2 . The key step 5 → 6 involves an asymmetric, electrophilic enolate hydroxyamination. Diastereoselective hydrogenation of nirtone 6 ensures the cis-relation between the substituents at C(2) and C(6) in piperidine 7 .