New synthetic routes to furans and dihydrofurans from 1-propargylbenzotriazole
摘要:
Base-assisted cyclizations of 1-[3-[hydroxy(substituted methyl)]propargyl]benzotriazoles, derived from lithiated 1-propargylbenzotriazole (1) and aromatic aldehydes or ketones, gave 2-arylfurans 5 or 1-(5,5-diaryl-2,5-dihydrofuran-2-yl)benzotriazoles 7, respectively, in high yields. Compounds 7 with Grignard reagents yielded trisubstituted 2,5-dihydrofurans 9.