4,6-Dichloro-2-oxa-5-azabicyclo[2.2.2]oct-5-en-3-ones and their Use in the Synthesis of 1,6-Dihydro-6-oxo-2-pyridine- and 6-Oxo-2-piperidinecarboxylates
摘要:
4,6-Dichloro-2-oxa-5-azabicyclo[2.2.2]oct-5-en-3-ones obtained from cycloaddition of 2H-1,4-oxazin-2-ones and alkene compounds, undergo lactone cleavage with alcohols to yield 1,4,5,6-tetrahydro-5-hydroxy-6-oxo-2-pyridnecarboxylates which can be dehydrated or reduced to a afford 1,6-dihydro-6-oxo-2-pyridine- or 6-oxo-2-pipcridinecarboxylates.
Generation of polysubstituted 2-pyridinecarboxylic acid derivatives from the reaction of (functionalised) 2-oxa-5-azabicyclo[2.2.2]oct-5-en-3-ones with various nucleophiles
作者:Kristof J. Dubois、Christine C. Fannes、Suzanne M. Toppet、Georges J. Hoornaert
DOI:10.1016/0040-4020(96)00733-8
日期:1996.9
By selective reaction of the chlorimine function in the adducts 2 from 3,5-dichloro-2H-1,4-oxazin-2-ones and double bond systems, a series of 6-substituted 2-oxa-5-azabicyclo[2.2.2]oct-5-en-3-ones 3 could be generated. Lactone cleavage of the latter with alcohols or amines yielded variously substituted 4,5-dihydro-5-hydroxy-2-pyridinecarboxylic acidderivatives which were dehydrated to afford the corresponding
通过3,5-二氯-2 H -1,4-恶嗪-2-酮和双键体系中加合物2中氯亚胺官能团的选择性反应,形成一系列6-取代的2-恶唑-5-氮杂双环[2.2] .2]可以生成oct-5-en-3-ones 3。用醇或胺将后者的内酯裂解,得到各种取代的4,5-二氢-5-羟基-2-吡啶羧酸衍生物,将其脱水以得到相应的吡啶体系。通过使2与Me 3 Al /胺反应,可在一步步骤中获得一些6-氨基取代的2-吡啶甲酰胺。
A new pathway to substituted 6-chloro-2-pyridinecarboxylic acid derivatives from the reaction of 4,6-dichloro-2-oxa-5-aza-bicyclo[2.2.2]oct-5-en-3-ones with nucleophiles
作者:Kristof J. Dubois、Georges J. Hoornaert
DOI:10.1016/0040-4020(96)00304-3
日期:1996.5
Reaction of alcohols or amines with 4,6-dichloro-2-oxa-5-azabicyclo[2.2.2]oct-5-en-3-ones gives direct conversion into (3,(4,))5-substituted 6-chloro-2-pyridinecarboxylic acidderivatives via selective lactone cleavage followed by rapid elimination of HCl and H2O in the presence of DBU.
Stereoselective Transformation of 2H-1,4-Oxazin-2-ones into 2,(2),5,5-Tri- and Tetrasubstituted Analogues of cis-5-Hydroxy-2-piperidinemethanol and cis-5-Hydroxy-6-oxo-2-piperidinecarboxylic Acid
2,(2),5,5-Tri- and tetrasubstituted analogues of 5-hydroxy-2-piperidinemethanol and 5-hydroxy-6-oxo-2-piperidinecarboxylic acid have been prepared via Diels-Alder reaction of 3-substituted 2H-1,4-oxazin-2-ones with ethene followed by functional group transformation of the resulting imidoyl chloride and lactone groups. Some of the 2-piperidinemethanol products are converted further into potential substance P antagonists. (C) 2000 Elsevier Science Ltd. All rights reserved.