An (S)-(+)-lactic acid route to (2S,6R,8S)-2,8 dimethyl-1,7-dioxaspiro[5,5]undecane and (2S,6R,8S)-2-ethyl-8-methyl-1,7-dioxaspiro[5,5]undecane and demonstration of their presence in the rectal glandular secretion of Bactrocera nigrotibialis(Perkins)
作者:Michael V. Perkins、William Kitching、Wilfrid A. König、Richard A. I. Drew
DOI:10.1039/p19900002501
日期:——
Z)isomers was achieved by preparative gas chromatography. GC analysis of these samples and of the rectal glandular secretion of male Bactrocera nigrotibialis, using a cyclodextrin-based phase, demonstrated that the (2S,6R,8S)-stereoisomers of the 2,8-dimethyl- and 2-ethyl-8-methyl-1,7-dioxaspiro[5.5]undecanes were the natural products, with no detectable level of the antipodes.
由(S)-(+)-乳酸乙酯的四氢吡喃-2-基醚的还原和碘化得到的手性碘化物已被加入到丙烯腈的自由基加成中。在与戊-4-烯基溴化镁反应时,得到的保护的亚硝酸羟基酯得到(S)-2-四氢吡喃-2-基氧基十一烷基-10-en-6-。在可逆条件下,使用酸性四氢呋喃水溶液对该羟基烯酮进行氧化汞化,同时进行脱保护和环化反应,并用硼氢化钠进行原位双相脱汞,从而提供基本上立体化学纯的(2 S,6 R,8 S)-2,8-二甲基-1,7-二氧杂螺[5.5]十一烷[即(E,E)-仅非对映异构体]。受保护的羟基烯酮的环氧化,接着dimethylcuprate开环和环化,提供的混合物(ë,ë)和所述两个可能的(Ë,Ž的)-diastereoisomers 2-乙基-8-甲基1,7- dioxaspiro [5.5]十一烷,前者为(2 S,6 R,8 S)立体异构体。通过制备型气相色谱将(E,E)与两种(E,Z)异构体