作者:Rudolf O. Duthaler、Peter Maienfisch
DOI:10.1002/hlca.19840670326
日期:1984.5.2
Alkylation of bicyclo[3.3.0]octane-2,8-dione (1), which is prepared by a modification of the procedure described in the literature, gives the methyl- and propynyl-derivatives 6 and 7 (Scheme 1). In addition to the method described previously (Scheme 2), 9-methyl-cis-decalin-1,8-dione 9 is obtainable stereoselectively either by cyclization of keto-acid 16, or by aldol cyclization of keto-aldehyde 26
通过修改文献中描述的方法制备的双环[3.3.0]辛烷-2,8-二酮(1)的烷基化得到甲基和丙炔基衍生物6和7(方案1)。除了先前描述的方法(方案2)以外,还可以通过酮酸16的环化或酮醛26的醛醇环化和羟基的26-羟基氧化来立体选择性地获得9-甲基-顺式-十氢化萘-1,8-二酮9。得到的醇24和25(方案4)。β-酮醇24和25进行碱催化的异构化; 所述反式-decalin异构体27和28在该平衡混合物(没有检测到方案4和5)升。顺式-二酮9的单还原得到内醇25,而反式-二酮10的还原蛋白则有利于产物27(方案4)。旋光纯的(+) - 25可从(9来制备小号,10 - [R)-monoacetal 29(流程5)。