New total synthesis of (+)-N-methylanisomycin by anodic cyclization of δ-alkenylamine
作者:Masao Tokuda、Hirotake Fujita、Tohru Miyamoto、Hiroshi Suginome
DOI:10.1016/s0040-4020(01)86320-1
日期:1993.3
A chiral total synthesis of (+)-N-methylanisomycin (1a) from L-diethyl tartrate via 15 steps is reported. The key step in the synthesis was a regio- and stereoselective cyclization of (E)-δ-alkenylamine 12a or its (Z)-isomer 12b by anodic oxidation of their lithium amides to give a substituted pyrrolidine 20. Thus, A Wittig reaction of 4-O-acetyl-2,3-O-bis (methoxymethyl)-L-threose (15), derived from
据报道,酒石酸L-二乙酯通过15个步骤手性全合成(+)- N-甲基茴香霉素(1a)。合成中的关键步骤是(E)-δ-链烯基胺12a或其(Z)-异构体12b的区域和立体选择性环化反应,方法是将其锂酰胺进行阳极氧化,得到取代的吡咯烷20。因此,经由6步衍生自酒石酸L-二乙酯的4- O-乙酰基-2,3- O-双(甲氧基甲基)-L-苏糖(15)与4-甲氧基苯基亚甲基-三苯基膦烷的Wittig反应得到(E)和(Z)-(3S,4S)-5-乙酰氧基-3,4-双[((甲氧基甲基)氧基] -1-(4-甲氧基苯基)戊-1-烯(16a和16b),产率为78% 。乙酸盐16a或d16b的水解,然后Swern氧化,以93%的收率得到相应的取代的5-(4-甲氧基苯基)五-4-烯醛17a或17b。用甲胺对醛17a或17b进行还原胺化,得到(E)-或(Z)-(2 S,3 S)-N-甲基-2,3-双[(甲氧基甲基)氧基] -