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
Fetching data from CrossRef. This may take some time to load.
Journal of the Chemical Society, Perkin Transactions 1
- Information Point