Intramolecular Reactivity of Arylcarbenes: 2-(Alkoxymethyl)phenylcarbenes

Article abstract of DOI:10.1016/0040-4039(94)88323-8

Both singlet and triplet states contribute to the intramolecular C-H insertion reactions of 2-(alkoxymethyl)phenylcarbenes, leading to dihydro-1H-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.