Process for the preparation of alkylidenecyclopentanone derivatives
申请人:Chapuis Christian
公开号:US20050187299A1
公开(公告)日:2005-08-25
The present invention relates to the field of organic synthesis and more particularly to a new process for the preparation of a compound of formula (I), in the form of any one of its isomers or a mixture thereof,
wherein, more preferably, G represents a C═O group, R
1
represents a butyl group and R
2
represents a methyl group.
The process of the invention involves an 2-(1-hydroxyalkyl)-cyclopent-2-en-1-one derivative, as starting material, which can be then converted into a compound of formula (I) by a process comprising a thermal rearrangement. The 2-alkylidene-3-oxo-cyclopentylacetate derivative and the 2-(1-hydroxyalkyl)-cyclopent-2-en-1-one derivative are also an object of the invention.
The exocyclically unsaturated conjugated keto esters 10, obtained via a Claisen ortho ester rearrangement of the allylic hydroxy ketones 9, were either directly hydrogenated or partially isomerized into the endocyclically unsaturated tetrasubstituted didehydrojasmonoid intermediates 14, prior to a more selective hydrogenation with Pd/C in cyclohexane to the disubstituted oxocyclopentaneacetates 15