Die bildung von thiirenen

Photochemical nitrogen elimination of 1,2,3-thiadiazoles leads to primary fragments ( 1 , X = S), which are able to cyclize to thiirenes ( 2 , X = S). An exception is found for bicyclic systems like 4 . These results, gained by isotope labelling experiments are related to the oxirene formation of α-oxocarbenes.