Oxy-Cope Rearrangements of Bicyclo[3.2.0]heptenones. Synthesis of Bicyclo[4.2.1]non-1(4)-en-6-ones and Bicyclo[5.2.1]dec-1(10)-en-5-ones
作者:Sharad K. Verma、Que H. Nguyen、James M. MacDougall、Everly B. Fleischer、Harold W. Moore
DOI:10.1021/jo991765w
日期:2000.6.1
1]non-1(4)-en-6-ones and the latter to the first examples of bicyclo[5.2.1]dec-1(10)-en-5-ones, compounds having exceptionally strained bridgehead double bonds. The transformations are controlled by the 6-exo-methyl group in the starting material along with the substituent at position-1 (bridgehead) which force attack of the lithium reagent from the concave face of the starting material, thus allowing the cyclopentenyl
6-异-甲基双环[3.2.0]庚-7-酮及其2-亚烷基类似物可容易地由二烷基二烷基酯制备。这些化合物在用乙烯基锂处理后会发生面部氧-Cope环膨胀;前者导致双环[4.2。1] non-1(4)-en-6-ones和后者为双环[5.2.1] dec-1(10)-en-5-ones的第一个实例,这些化合物具有异常应变的桥头双键。转化受起始材料中的6-外甲基以及位置1(桥头)上的取代基控制,该取代基迫使锂试剂从起始材料的凹面进攻,从而形成环戊烯基或亚烷基参加大型活动。