Synthesis of (?)-Pinidinevia asymmetric, electrophilic enolate hydroxyamination/nitrone reduction
作者:Wolfgang Oppolzer、Eric Merifield
DOI:10.1002/hlca.19930760218
日期:1993.3.24
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.
对映体纯的(-)-吡啶(1)已通过从酮酸酯2开始的九步法合成,以18.5%的总收率合成。关键步骤5 6涉及不对称的亲电烯醇式羟基胺化。内酯6的非对映选择性氢化可确保哌啶7中C(2)和C(6)处的取代基之间具有顺式关系。