作者:Raymond Baker、Ian F. Cottrell、Paul D. Ravenscroft、Christopher J. Swain
DOI:10.1039/p19850002463
日期:——
and reduction with lithium aluminium hydride gave mixtures of two diols in each case. Treatment of each mixture with toluene-p-sulphonyl chloride gave the four stereoisomers of ancistrofuran. A stereoselective synthesis was also developed to the trans-fused ancistrofuran which was identical with the natural isomer. Lactol (22) was conveniently prepared by di-isobutyl aluminium hydride reduction of lactone
顺呋喃的四种可能的立体异构体是由γ-环同型制备的。加入3-呋喃基锂产生两种差向异构醇。每个醇用环氧化的米氯过苯甲酸和还原用氢化铝锂中得到两种二醇的混合物在每种情况下。用甲苯-对-磺酰氯处理每种混合物,得到顺呋喃的四种立体异构体。还开发了与天然异构体相同的立体选择性合成至反式融合的顺呋喃呋喃。乳醇(22)中的溶液方便地由二异丁基氢化铝还原内酯(制备23)。乳糖醇与2摩尔当量的反应 用3-呋喃基锂制得比例为3∶1的两种二醇的混合物。用二氧化锰氧化得到酮(24),其以高度立体选择性的方式用三乙基硼氢化锂还原,得到二醇(13)。通过内酯(23)与1摩尔当量的反应也一步制备酮(24)。3-呋喃基锂。随后用甲苯-对-磺酰氯处理二醇(13),得到与天然产物相同的顺呋喃。已经讨论了γ-羟基酮的立体选择性还原,并建议涉及“螯合控制”。