ELECTRONIC EFFECTS ON THE <i>CIS</i>/<i>TRANS</i> SELECTIVITY IN FORMATION OF ISOXAZOLIDINE-FUSED EIGHT-MEMBERED RING <i>VIA</i> AN INTRAMOLECULAR NITRONE-ALKENE CYCLOADDITION

Abstract

An intramolecular nitrone-alkene cycloaddition involving in situ generated nitrones demonstrated reaction profiles different from those previously reported for pyrimidine system. Tuning the electron density of the benzene ring had a significant effect on cis/trans selectivity. These reactions were useful for the synthesis of novel tricyclic hexahydrobenzo[b]isoxazolo[3,4-f][1,4]diazocin-4(1H)-ones and hexahydroisoxazolo[3,4-f]pyrido[3,2-b][1,4]diazocin-4(1H)-one under mild reaction conditions in good yields.