Stereospecific synthetic routes to methyl (R)-7-hydroxy-(2E,4E)-octadienoate (9) and its (2E,4Z)-isomer (16), the former which can be a useful chemical precursor to the 16-membered-ring aglycon of carbomycin B (carbonolide B), are discussed. Compound 9, corresponding to its C-9–C-16 segment, was synthesized starting with methyl 2-deoxy-α-D-arabion-hexopyranoside (2). The deoxysugar 2 was converted to the masked
(R)-7-羟基-(2E,4E)-
辛二烯酸甲酯 (9) 及其 (2E,4Z)-异构体 (16) 的立体特异性合成路线,前者可以是 16 元的有用
化学前体讨论了卡霉素 B (carbonolide B) 的 -环苷元。化合物 9 对应于其 C-9-C-16 片段,是从甲基 2-脱氧-α-D-阿拉伯酮-
吡喃己糖苷 (2) 开始合成的。脱氧糖 2 通过 4,6-二
氯-2,4,6-三脱氧-α-D-lyxo-hexopyranoside 衍
生物转化为掩蔽的 2,4,6-trideoxy-D-threo-hexopyranose (6)。6 用
对甲苯磺酰氯和
三乙胺处理得到 3-O-乙酰基-1,5-脱
水-2,4,6-三脱氧-D-threo-hex-1-enitol,它与
乙酸汞(II)反应转化为 (R)-5-羟基-(2E)-
己烯醛 (8)。8 与 Wittig 试剂反应得到 (2E,4E)-异构体 9。