Upon photolysis in methylene chloride at −78 °C, different N-chlorolactams underwent a novel ring contraction to the corresponding carbamoyl chlorides, which were converted to the methyl carbamates. The rearrangement is 100% stereoselective, occurring with retention of configuration at the migrating carbon center. The yields of isolated carbamates ranged from 40% to 57%, the other product being the
在-78°C的
二氯甲烷中光解后,不同的N-
氯内酰胺发生新的环收缩,生成相应的
氨基
甲酰氯,然后将其转化为
氨基甲酸甲酯。重排是100%立体选择性的,发生构型保留在迁移的碳中心。分离的
氨基甲酸酯的产率为40%至57%,另一种产物为母体内酰胺,产率为18%至38%。