Duffy Jeffy L., Kurth Mark J., J. Org. Chem, 59 (1994) N 14, S 3783-3785
作者:Duffy Jeffy L., Kurth Mark J.
DOI:——
日期:——
A Novel Intramolecular Silyl Nitronate Cycloaddition Route to Dihydrofuraldehydes and Dihydropyranaldehydes
作者:Jetty L. Duffy、Mark J. Kurth
DOI:10.1021/jo00093a009
日期:1994.7
The novel transformation (1 --> 3) of propargylic or homopropargylic nitroethers to dihydrofuraldehydes (n = 0) or dihydropyranaldehydes (n = 1) is reported. The transformation proceeds by a silyl nitronate olefin cycloaddition to an N-[(trimethylsilyl)oxy]isoxazolidine intermediate which, upon acid workup, undergoes desilylation with subsequent elimination of hyponitrous acid to 3.
A Facile Synthesis of 3,4-Disubstituted Isoxazole Derivatives by Regioselective Cleavage of Pyrano[3,4-<i>C</i>]Isoxazoles with Boron Trihalide
作者:Hyung JinKim、Young JuLee
DOI:10.1080/00397919808004899
日期:1998.10
4-c]isoxazoles 4 were efficiently prepared by the intramolecular nitrile oxide-alkyne cycloaddition following the Michael addition of sodium alkoxide to nitroalkene. Reaction of pyrano[3,4-c]isoxazole 4 with boron trihalide resulted in regioselective benzylic C-O bond cleavage to furnish a 3,4-disubstituted isoxazole (5, 6) in high yield.