Preparation of unsaturated α,α-dichloro acid chlorides and intramolecular [2 + 2] cycloadditions of the α-chloroketenes reductively generated from them. Effect of double bond geometry on the cycloaddition
作者:Barry B. Snider、Marleen Walner
DOI:10.1016/s0040-4020(01)80143-5
日期:1989.1
Reduction of unsaturatedα,α-dichloracid chlorides with zinc dust in THF at reflux generates an unsaturated α-chloroketene which undergoes an intramolecular [2 + 2] cycloaddition in good yield. This reaction can be used with three carbon tethers to prepare 5-chlorobicyclo[3.2.0]heptan-6-ones and 1-chlorobicyclo[3.1.1]heptan-6-ones but fails with larger tethers. Unsaturated ketenes 18 and 28, with a