An asymmetric synthesis of 4,4- and 6,6-dialkylcyclohexenones and 4,4- and 5,5-dialkylcyclopentenones. Application to the total synthesis of (-)-silphiperfol-6-ene
作者:A.I. Meyers、Bruce A. Lefker
DOI:10.1016/s0040-4020(01)87745-0
日期:1987.1
Chiral amino alcohols have been transformed into bicyclic lactams 1 and 6 which, after metalation and alkylation, gave high diastereomeric ratios of 2,2-dialkyl quaternary products, 29 and 12, respectively. Addition of organolithium reagents to the carbonyl of these lactams, followed by acidic cleavage, leads to enantiomerically pure cyclohex-2-enones and cyclopent-2-enones. This process was also applied
手性氨基醇已被转化为双环内酰胺1和6,在金属化和烷基化后,它们分别具有较高的非对映体比例,即2,2-二烷基季铵盐29和12。将有机锂试剂加到这些内酰胺的羰基上,然后进行酸裂解,得到对映体纯的环己-2-烯酮和环戊-2-烯酮。此过程也应用于关键的手性环戊烯酮39,Curran以外消旋形式使用该手性环戊烯酮39来制备角三喹烷,silphiperfol-6-ene。在九个步骤中以6.6%的产率进行了总的不对称合成。