The first generation of a new sulfur-functionalized nitrile oxide 1,3-dipole, (phenylthio)acetonitrile oxide, is presented. Its cycloadditions to a variety of olefins and acetylenes lead to 3-(phenylthiomethyl)-2-isoxazolines and -oxazoles, the formers being selectively deprotonated at the carbon substituted by the sulfur moiety. The resulting sulfur-stabilized carbanions react with aldehydes, esteric
Synthesis of the Aziridinomitosene Skeleton by Intramolecular Michael Addition: α-Lithioaziridines and Nonaromatic Substrates
作者:Edwin Vedejs、Jeremy D. Little、Lisa M. Seaney
DOI:10.1021/jo030224a
日期:2004.3.1
The bicyclic pyrrole ketone 16 has been prepared by using an oxaza-Claisen rearrangement, followed by nitrogen deprotection. Coupling with the stannylaziridine mesylate 15a or nosylate 15b affords 17. Conversion to 40 provides a substrate for generation of an α-lithioaziridine 41 by tin lithium exchange. An intramolecular Michael addition pathway for 41 has been demonstrated by the isolation of 46