Synthesis of spiro[4.5]decane and bicyclo[4.3.0]nonane ring systems by self-cyclization of (Z)- and (E)-2-(trimethylsilylmethyl)pentadienal derivative
作者:Chiaki Kuroda、Shigenobu Honda、Yuki Nagura、Hiroyuki Koshio、Taku Shibue、Tokio Takeshita
DOI:10.1016/j.tet.2003.11.024
日期:2004.1
which was isomerized to the above product. The cyclization of 4-(4-alkyl)cyclohexylidene-2-(trimethylsilylmethyl)but-2-enal proceeded stereoselectively. While, (E)-3-(cyclohex-1-en-1-yl)-2-(trimethylsilylmethyl)prop-2-en-1-al cyclized immediately affording 8-methylenebicyclo[4.3.0]non-9-en-7-ol. The corresponding (Z)-isomer gave several cyclization products as a complex mixture.
利用一种新型的铁诱导的2-(三甲基甲硅烷基甲基)戊二烯醛环化反应合成了两个标题碳骨架。从(Z)-和(E)-4-环己叉基-2-(三甲基甲硅烷基甲基)丁-2-烯醛获得2-甲基螺[4.5] dec-2-en-1-one 。发现(Z)-底物异构化为(E)-中间体,然后环化,得到初始产物2-亚甲基螺[4.5] dec-3-en-1-ol,其异构化为上述产物。4-(4-烷基)亚环己基-2-(三甲基甲硅烷基甲基)丁-2-烯的环化是立体选择性地进行的。而,(E)-3-(环己-1-烯-1-基)-2-(三甲基甲硅烷基甲基)prop-2-en-1-al立即环化,得到8-亚甲基双环[4.3.0] non-9-en-7-ol 。相应的(Z)-异构体给出了几种环化产物,为复杂的混合物。