195613-96-8Relevant articles and documents
Synthesis of pyrrolizin-3-ones by flash vacuum pyrolysis of pyrrol-2-ylmethylidene Meldrum's acid derivatives and 3-(pyrrol-2-yl)propenoic esters
Campbell, Shirley E.,Comer, Murray C.,Derbyshire, Paul A.,Despinoy, Xavier L. M.,McNab, Hamish,Morrison, Roderick,Sommerville, Craig C.,Thornley, Craig
, p. 2195 - 2202 (2007/10/03)
Monosubstituted pyrrolizin-3-ones 1 with substituants 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.
