Cycloaddition of dichloroketene with functionalized cycloalkenes, synthesis of bicyclo[4.2.0]octanone-3-yl derivatives and of 3,4- dicarbomethoxy-1-methylbicyclo [4,2,0] octan-7-one
作者:Goffredo Rosini、Roberto Ballini、Valerio Zanotti
DOI:10.1016/s0040-4020(01)91870-8
日期:1983.1
carbon atoms. In fact acetate and benzoate of 3,5,5-trimethylcyclohex-3-en-1-ol and 1,2-dicarbo-methoxy-4-methyl-cyclohex-4-ene undergo 2+2 cycloaddition of dichloroketene to produce the corresponding bicyclo[4.2.0]octanone derivatives in 60–65% yield. In the latter case the process occurs regiospecifically to give 3,4-dicarbomethoxy-1-methylbi-cyclo[4,2.0]octan-7-one as product after dechlorination. The
二氯乙烯烯与一些环烯烃反应,其中酯官能团相对于sp 2碳原子处于均烯丙基或什至更遥远的位置。实际上,3,5,5-三甲基环己-3-烯-1-醇的乙酸盐和苯甲酸酯和1,2-二苯甲氧基甲氧基-4-甲基-环己-4-烯经过2 + 2环化二氯乙烯酮生成相应的双环[4.2.0]辛烷酮衍生物,收率60-65%。在后一种情况下,该方法在区域上特异性地发生,从而在脱氯后得到3,4-二苯甲氧基-1-甲基双环[4,2.0] octan-7-one。生成二氯乙烯酮的Hassner锌脱卤法是最好的方法。