Methylated multibridged [2n]cyclophanes. All alternate synthesis of [26](1,2,3,4,5,6) cyclophane (superphane)
作者:William D. Rohrbach、Robert Sheley、V. Boekelheide
DOI:10.1016/s0040-4020(01)91315-8
日期:1984.1
bridges into 4,5,7,8- tetramethyl [22](1,4)cyclophane (), providing syntheses of 5,7,8-trimethyl- [23](l,2,4)cyclophane (), a mixture of 5,8-dimethyl[24(1,2,4,5)cyclophane () and 5,7-dimethyl[24(1,2,3,5)cyclophane (, and-4-methyl[25](1,2,3,4,5)-cyclophane (). This route to completes a formal eight-step synthesis of [26](1,2,3,4,5,6)cyclophane (, superphane) with an overall yield of 17%. A Birch reduction
一系列甲酰化反应以及随后的卡宾插入反应导致将额外的乙醇桥逐步引入4,5,7,8-四甲基[2 2 ](1,4)环烷()中,提供了5,7, 8-三甲基-[2 3 ](1,2,4)环烷(),5,8-二甲基[2 4(1,2,4,5)环烷()和5,7-二甲基[2 4(1,2,3,5)cyclophane(和4-methyl [2 5 ](1,2,3,4,5)-cyclophane()。此路线完成[[ 2 6 ](1,2,3,4,5,6)环烷(,superphane),总收率为17%。桦木还原很容易得到12,15-dihydro-5,7,8-trimethyl [23 ](1,2,4)-环烷(),产率为85%。