694528-29-5Relevant academic research and scientific papers
Synthesis of cis-Hedione and methyl jasmonate via cascade Baylis-Hillman reaction and Claisen ortho ester rearrangement
Chapuis, Christian,Buechi, George H.,Wueest, Hans
, p. 3069 - 3088 (2007/10/03)
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 (Scheme 2). The key intermediates 9 were obtained either by a four-step sequence, including acetal protection/deprotection from enone 1, in the specific case of hydroxy ketone 9a (Scheme 1), or more directly and generally by a Baylis-Hillman reaction from cyclopent-2-en-1-one (16) and the appropriate aldehydes 17 (Scheme 2). The judicious choice of these aldehydes opens versatile modifications for the stereoselective introduction of the partially cis- or epimerized trans-C(2) jasmonoid side chain, while the Baylis-Hillman reaction, catalyzed by chiral [1,1′-binaphthalene]-2, 2′-diols (BINOLs) 19 (Scheme 3), may be efficiently conducted in a one-pot cascade fashion including the ortho ester Claisen rearrangement.
A PROCESS FOR THE PREPARATION OF ALKYLIDENECYCLOPENTANONE DERIVATIVES
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Page 6; 7, (2008/06/13)
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, Formula (I) wherein, more preferably, G represents a C=O group, R1 represents a butyl group and R2 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.
