Synthesis of pyrrolizin-3-ones by flash vacuum pyrolysis of pyrrol-2-ylmethylidene Meldrum’s acid derivatives and 3-(pyrrol-2-yl)propenoic esters
Autor: | Craig C. Sommerville, Shirley E. Campbell, Paul A. Derbyshire, Hamish McNab, C. Thornley, Roderick Morrison, Xavier L. M. Despinoy, M. C. Comer |
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Rok vydání: | 1997 |
Předmět: | |
Zdroj: | Journal of the Chemical Society, Perkin Transactions 1. :2195-2202 |
ISSN: | 1364-5463 0300-922X |
Popis: | Monosubstituted pyrrolizin-3-ones 1 with substituents at the 1-, 5-, 6- or 7-positions are prepared in excellent yield by flash vacuum pyrolysis (FVP) of appropriate Meldrum’s acid derivatives 2. The mechanism involves formation of the pyrrol-2-ylmethylideneketene 29, which can also be generated thermally from 3-(pyrrol-2-yl)propenoate esters (e.g. 30). This alternative route has been used to make a range of 2-substituted pyrrolizin-3-ones, again in excellent yield. The 3-oxo-3H-pyrrolizine-2-carboxylic acid 42 could not be made in this way owing to facile decarboxylation to pyrrolizinone 1, and extension to the formation of the azaazulenone 48 was again unsuccessful. |
Databáze: | OpenAIRE |
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