Novel 1-(2-,3- or 4-hydroxylaminobenzensulfonyl-1a,2,6,6 a-tetrahydro-1H,4H-[1,3]-dioxepino[5,6-b]azirines with hypoglycemic activity are prepared by selective reduction of appropriate 1-(2-,3- or 4-nitrobenzenesulfonyl) derivatives.