1, 3-Dioxepin

Abstract

Dioxygenated 1, 3-butadienes are of considerable interest as the diene components in stereoselective syntheses involving the Diels-Alder reaction. Available dienes include trans 1-methoxy-3-t rimethylsilyloxy-1,3-butadiene, 2,3-dimethoxi-l, 3-butadiene, and the several stereoisomers of 1, 4-diacetoxy-1,3-butadiene. Recently, E,E 1,4-diacetoxy-2-methyl-1, 3-butadiene and its stereoisomers have been described. 1.3-Dioxepin, heretofore unknown, attracted our attention since one of the stereoisomers might be more reactive .in a Diels-Alder reaction than the open chain i,4-dioxygenated dienes owing to the requisite conformation of the 1.3-diene system. Also, the possibility exists that reaction with certain dienophiles could lead to adducts, the stereochemistry may be opposite to that of adducts derived from the open chain E,E 1,4-diacetoxy-l,3-diene.