Katritzky A R, Button M A
Center for Heterocyclic Compounds, Department of Chemistry, University of Florida, Gainesville, 32611-7200, USA.
J Org Chem. 2001 Aug 10;66(16):5595-600. doi: 10.1021/jo001571c.
alpha-(Benzotriazolyl)methyl thioethers 1a-e reacted with styrenes under Lewis acid catalysis to give novel polysubstituted thiochromans (3,4-dihydro-2H-1-benzothiopyrans) 3-14 and 16-20 in generally high yields. Most thiochromans were isolated as one diastereomer following recrystallization. The configuration and conformation of the products are predicted on the basis of their NMR data. A stepwise reaction, proceeding via a [4(+) + 2] cationic polar cycloaddition mechanism, is proposed.
