Reaction of diazoalkanes on the activated C(4)–C(5) isoxazole double bond: a new entry to the 2-oxa-3-azabicyclo[3.1.0]hex-3-ene ring system
Abstract
The nitroester (1) was shown to give rise to 1,3-dipolar cycloadditions with diazomethane and 2-diazopropane,affording the bicyclic derivatives (4) and (5)via the unstable primary cycloadducts (2) and (3), respectively.