Reactions of readily available and stable 1-(α-alkoxyalkyl) benzotriazoles type 9a, b and 10a–d with a variety of silyl enol ethers 11 or 1, 3-dicarbonyl compounds 13 give the expected ketones 12a–l (60–92%), β-keto esters 14a, b (62–67%), and malonates 14c, d (79–88%) in which a tetrahydrofuran or tetrahydropyran moiety has been introduced at the α position. 1-(Benzotriazol-1-yl) alkyl esters 7 are converted by cyanide anion into ...
