Analogues ofα-Campholenal (= (1R)-2,2,3-Trimethylcyclopent-3-ene-1-acetaldehyde) as Building Blocks for (+)-β-Necrodol (= (1S,3S)-2,2,3-Trimethyl-4-methylenecyclopentanemethanol) and Sandalwood-like Alcohols
作者:Christian Chapuis、Michel Barthe、Carole Cantatore、Christine Saint-Léger、Patrick Wyss
DOI:10.1002/hlca.200690236
日期:2006.11
relationships (SARs) of sandalwood-like alcohols derived from analogues of α-campholenal (= (1R)-2,2,3-trimethylcyclopent-3-ene-1-acetaldehyde), we isomerized the epoxy-isopropyl-apopinene (−)-2d to the corresponding unreported α-campholenal analogue (+)-4d (Scheme 1). Derived from the known 3-demethyl-α-campholenal (+)-4a, we prepared the saturated analogue (+)-5a by hydrogenation, while the heterocyclic aldehyde
为了完成我们从α-樟脑醛(=(1 R)-2,2,3-三甲基环戊-3-烯-1-乙醛)类似物衍生的檀香状醇的构效关系(SAR)的全景图,我们进行了异构化将环氧-异丙基-Apopinene(-)- 2d转化为相应的未报告的α- campholenal类似物(+)- 4d(方案 1)。从已知的3-去甲基衍生的α -campholenal(+) - 4a中,我们制备的饱和类似物(+) - 5a中通过氢化,而杂环醛(+) - 5b中获得经由一个拜耳维利格由已知的甲基酮(+)- 6反应。在随后将醇(+)- 9b氧化为酮(+)- 10并进行适当的烷基Grignard反应后,可以将已知的α-樟脑缩醛(-)- 8b进行氧化硼氢化处理,从而获得3,4-二取代的类似物( +)-脱水和脱保护后的4f,g。(方案 2)。(+)- 4b或其甲基酮(+)- 4h的环氧化,立体选择性地提供了反式-环氧衍生物11a,b,而次要的顺式-立体异构体(+)-