triplet states contribute to the intramolecular CH insertion reactions of 2- (alkoxymethyl)phenylcarbenes, leading to dihydro-1 H-2-benzopyrans. Competitively, oxygen ylides are generated which eventually give rise to benzocyclobutenes and dihydroisobenzofurans. The radical pair mechanism of the Stevens rearrangement is confirmed by variation of the alkyl groups and by means of chiral substrates.
单重态和三重态都有助于2-(烷氧基甲基)苯基卡宾的分子内CH插入反应,从而导致二氢-1 H -2-苯并
吡喃。竞争地,产生了氧化氧,最终产生了
苯并环丁烯和二氢
异苯并呋喃。史蒂文斯重排的自由基对机理通过烷基的变化和手性底物的证实。