Novel Photochemical Reaction of 2-(2-Alkynyl)acetophenones Initiated by Type II Abstraction

Article abstract of DOI:10.1016/S0040-4039(00)71210-X

Irradiation of 5a and 5b in methanol leads to formation of the diastereomeric methoxy alcohols 8a and 9a, and 8b and 9b, respectively.These reactions can be understood as involving type II abstraction of γ hydrogen, 1,5 cyclization of the resulting biradical 6 to form vinyl carbene 7 (as 1 -> 2), and then carbene insertion into the hydroxyl group of the solvent methanol.