1,3-Dipolar cycloadditions to 2,3-dimethoxycarbonyl-7-oxabicyclo[2,2,1]-2,5-heptadiene, 1,4-epoxy-1,4-dihydronaphthalene, and exo-endo-1,6-dimethoxycarbonyl-11,12-dioxatetracyclo-[4,4,0,12,5,17,10]-3,8-dodecadiene

Abstract

The paper deals with site-selectivity of 1,3-dipolar cycloadditions of ethyl azidoformate, azidoacetate, and diazo acetate to 2,3-dimethoxycarbonyl-7-oxabicyclo[2,2,1]-2,5-heptadiene. The exo-endo stereoselectivity has been studied of the reactions of 1,4-epoxy-1,4-dihydronaphthalene with C-benzoyl-N-phenyl- and C,N-diphenylnitrones, 5-azido-2-furanecarbaldehyde, 4-nitrophenylazide, benzenenitril oxide, ethyl azidoformate, azidoacetate, and diazo acetate. The cycloadditions to the bis-adduct of furane with dimethyl acetylenedicarboxylate and thermolyses of some of the adducts prepared have also been studied.