Synthesis of 18,18-difluoro- or 18,18,18-trifluoro-3-methoxy-12-oxaestra-1,3,5(10)-trienes
作者:Serge Wilmouth、Hélène Pellissier、Maurice Santelli
DOI:10.1016/s0040-4020(98)00599-7
日期:1998.8
Titanium tetrachloride mediated dialkylation of acetic anhydride, trifluoroacetic anhydride or difluorochloroacetic anhydride by 1,8-bis(trimethylsilyl)-2,6-octadiene (BISTRO) leads, respectively, to dl-1-methyl-2,5-divinylcyclopentan-1-ol, dl-1-difluoromethyl-2,5-divinylcyclopentan-1-ol or dl-1-trifluoromethyl-2,5-divinylcyclopentan-1-ol. Esterification of these compounds with 4-methoxybenzocyclobutene-1-carboxylic
四氯化钛介导的1,8-双(三甲基甲硅烷基)-2,6-辛二烯(BISTRO)对乙酸酐,三氟乙酸酐或二氟氯乙酸酐的二烷基化分别导致dl -1-甲基-2,5-二乙烯基环戊烷-1-醇,dl -1-二氟甲基-2,5-二乙烯基环戊烷-1-醇或dl -1-三氟甲基-2,5-二乙烯基环戊烷-1-醇。用4-甲氧基苯并环丁烯-1-羧酸酯化这些化合物,然后热解,生成3-甲氧基-12-氧杂-17-乙烯基lestra-1,3,5(10)-trien-11-one和相应的18,18。 -二氟或18,18,18-三氟衍生物。进一步的转化产生3-甲氧基-12-氧杂-17-(2-氧代乙基)-18,18-二氟雌激素-1,3,5(10)-三烯-11-一个和相应的18,18,18 -三氟衍生物。