The scope and mechanism of a novel synthesis of 3,4-fused isoxazoles
Abstract
Thermal cyclisation of 2-nitrophenyl- and 3-nitrohetaryl-ethanoate derivatives in xylene is facilitated indirectly by 5 Å molecular sieves affording an efficient general method for the construction of synthetically useful 3,4-fused isoxazoles; evidence for the mechanism of these novel heterocyclisation reactions is presented.