silica chloride, an eco-friendly heterogeneous catalyst, silica chloride–arenes, and silica chloride–saturated and unsaturatedalcohols as reagent systems are reported. These reactions furnished highly functionalized isomerized Baylis–Hillman derivatives in good yield. The efficiency and necessity of silica chloridecatalyst was compared with thionyl chloride. A plausible mechanism of the reaction is proposed
Regio- and stereoselective synthesis of methyl 5-methylenetetrahydropyran-3-carboxylates from Baylis–Hillman adducts via allyltributylstannane-mediated radical cyclization
作者:Saravanan Gowrisankar、Ka Young Lee、Taek Hyeon Kim、Jae Nyoung Kim
DOI:10.1016/j.tetlet.2006.05.186
日期:2006.8
Two types of regioisomeric methyl 5-methylenetetrahydropyran-3-carboxylate derivatives 3a–c and 6a–c were synthesized stereoselectively starting from the Baylis–Hillman adducts via the allyltributylstannane-mediated vinyl radical cyclization as the key step.