DIENOPHILIE DES OLEFINES CAPTODATIVES-VII: CYCLOADDITIONS DE DIELS-ALDER DE L'α-METHYLTHIO-ACRYLATE DE METHYLE, REACTIONS THERMIQUES, REACTIONS CATALYSEES PAR UN ACIDE DE LEWIS ET TRANSFORMATIONS DES ADDUITS

Article abstract of DOI:10.1016/S0040-4020(01)85990-1

The Diels-Alder reactions of the α-methylthio methyl acrylate with simple dienes are investigated.The uncatalyzed thermal reactions proceed in high yield.With cyclic dienes they give adducts in wich the carbonyl containing substituent of the major product occupied the exo position.We have shown that with cyclopentadiene the stereoselectivity decreases with increasing temperature.In the presence of a Lewis acid catalyst, the regioselectivity is enhanced and the stereoselectivity is radically reversed.The cycloadducts are amenable to further usefull transformations which illustrate that the α-methylthio methyl acrylate can be used as a synthetic equivalent of either ketene or methoxycarbonyl-acetylene.