The use of hetero-substituted 1, 3-dienes in Diels-Alder reactions has been an area of great synthetic activity.'The introduction of hetero substituents has a significant influence on the reactivity and regioselectivity of the diene, and these hetero substituents add versatility in further reactions of the cyc1oadducts. l The attachment of two hetero substituents at the 2- and 3-positions of a 1, 3-diene further increases the potential utility, and several studies ...
