Reversal of regiochemistry in the synthesis of isoxazoles by nitrile oxide cycloadditions
作者:Christopher J. Easton、C.Merrîcc Hughes、Edward R.T. Tiekink、Carolyn E. Lubin、G.Paul Savage、Gregory W. Simpson
DOI:10.1016/s0040-4039(00)73248-5
日期:1994.5
isoxazolines 2a, 2b and 8 obtained from nitrileoxidecycloadditions to cyclohex-2-enone 1a and its analogues 1b and 7 reacted with nickel peroxide to give the isoxazoles 3a, 3b and 9. In contrast, the corresponding 2-bromocyclohex-2-enones 4a, 4b and 10, prepared by bromination of the corresponding alkenes 1a, 1b and 7, underwent nitrileoxidecycloadditions to afford the regioisomeric isoxazoles 6a