1,3-Dihydro-2,2-dioxothieno[3,4-c]pyridines as precursors for pyridine o-quinodimethane systems
摘要:
Various pyridine o-quinodimethane systems were generated via thermal extrusion of sulfur dioxide from 1,3-dihydro-2,2-dioxothieno[3,4-c]pyridine precursors and derivatives functionalised in the 1- or 3-position of the sulfolene ring moiety. Depending on the nature of the peri-substituents on the pyridine ring either the E or Z-isomers are formed, which react further via inter- and intramolecular Diels-Alder reactions or via an 1,5-H shift, respectively. (C) 2001 Elsevier Science Ltd. All rights reserved.
Functionalized o-bis(chloromethyl)pyridines as precursors for pyridine o-quinodimethane analogues and their [4+2] cycloadducts
作者:Peter R. Carly、Frans Compernolle、Georges J. Hoornaert
DOI:10.1016/0040-4039(95)00169-d
日期:1995.3
From oxazinones 4, precursors for pyridine o-quinodimethaneanalogues are made accessible via cycloaddition with 1,4-dichloro-2-butyne and propargyl chloride. Subsequent 1,4-elimination of the polyfunctional o-bis(chloromethyl)-pyridines affords both 2,3- and 3,4-dimethylene compounds, which are trapped in situ with various dienophiles.