作者:S. Ramakanth、K. Narayanan、K.K. Balasubramanian、K. Rajagopalan
DOI:10.1016/s0040-4020(01)87493-7
日期:1986.1
A novel photochemical ring contraction of 6H-(benzofuro)(3,2-c)(1)11a,6a-dihydro-11a-methylbenzopyrans, 1 or shortly, 11a-methylpterocarpans to the respective 4b,9b-dihydro-4b,9b-dimethylbenzofuro(3,2-b)benzofurans 2 is reported. This transformation of 1 → 2 is envisaged to proceed through a mechanism involving the intermediacy of 6. An unusual acceleration of this photochemical rearrangement by bases
6H-(苯并呋喃)(3,2-c)(1)11a,6a-二氢-11a-甲基苯并吡喃,1个或简称为11a-甲基紫果烷的新颖光化学环收缩成相应的4b,9b-dihydro-4b,9b报道了-二甲基苯并呋喃(3,2-b)苯并呋喃2。设想这种1→2的转化将通过涉及6的中间机制进行。已经观察到这种光化学重排被碱基异常加速的现象。