Intramolecular Diels–Alder reactions of 2<i>H</i>-thiopyran dienes
作者:Dale E. Ward、Thomas E. Nixey、Yuanzhu Gai、Matthew J. Hrapchak、M. Saeed Abaee
DOI:10.1139/v96-160
日期:1996.7.1
the activated dienophile attached via a C3 tether to C-2 of the 2H-thiopyran gave adducts with high stereoselectivity. Substrates having the dienophile attached to C-3 with a C3 or C4 tether cyclized readily. With an (E)-enoate as the dienophile, the stereoselectivity was poor (endo:exo = 1.1–2.5:1) and essentially independent of reaction conditions (i.e., thermal vs. Lewis acid mediated). With the(Z)-enoate