140887-86-1Relevant academic research and scientific papers
Lipase-mediated resolution of the hydroxy-cyclogeraniol isomers: application to the synthesis of the enantiomers of karahana lactone, karahana ether, crocusatin C and γ-cyclogeraniol
Serra, Stefano,Gatti, Francesco G.,Fuganti, Claudio
experimental part, p. 1319 - 1329 (2009/12/01)
A comprehensive study on the lipase PS-mediated resolution of different hydroxy-geraniol isomers is reported. A number of α-, β- and γ-isomers bearing a 2-, 3- or 4-hydroxy functional group were synthesised regioselectively and then submitted to the lipase-mediated kinetic acetylation. The latter experiments showed that the 2-hydroxy isomers 4, 5 and 14 (α, γ and β, respectively) as well as cis-3-hydroxy α-cyclogeraniol 7 and cis-4-hydroxy γ-cyclogeraniol 10 could be easily resolved by this procedure. The enantiomeric purity of the main part of these compounds was increased by recrystallisation and the enantiopure diols obtained were used as building blocks for the synthesis of the natural terpenoids karahana lactone, karahana ether and crocusatin C and for the preparation of the synthetic intermediate γ-cyclogeraniol. The absolute configurations of the enantiomers of the diols 7, 10, 14 and 19 were determined by chemical correlation with the known compounds 40, 41, 39 and 41, respectively.
A synthetic approach to (+/-)-forskolin. Part I. Preparation of key hydrobenzofuran intermediates
Anies, Claude,Pancrazi, Ange,Lallemand, Jean-Yves
, p. 183 - 202 (2007/10/03)
In a synthetic approach to (+/-)-forskolin 1, a stereoselective preparation of the unsaturated lactone 2 was envisaged.Propargylic derivatives 18a-c were prepared from available α-ionone 5 and treated with Bu3SnH/AIBN to give the bicyclic vinylstannanes 19a-c in high yield.From these compounds we then performed transmetallation reactions to obtain the 21a-c and 22b homologous derivatives.The two enyne compounds 29 and 30 were then prepared by our previous approach to lactone 2 involving a radical C7-C8 bond formation.In a second radical approach promoted by SmI2, the diol 10, was used to synthesize a potential precursor of the dialdehyde 9. - Keywords: forskolin; tributylstannane; radical cyclization; transmetallation; vinylstannane; vinyl iodide; Pd(0) coupling reaction
Intramolecular coupling reaction promoted by SmI2 in a synthetic approach of forskolin
Anies, Claude,Pancrazi, Ange,Lallemand, Jean-Yves,Prange, Thierry
, p. 7771 - 7774 (2007/10/02)
From available hydroxy-aldehyde 6, propargylic derivative 8 was prepared and treated with Bu3SnH to give in 95% yield the biocyclic vinyl stannone 10. After 10 was converted into the diol 15, this latter was oxidized with the Dess-Martin reagents into the dialdehyde 4. Compound 4 was then submitted to a pinacolic coupling reaction leading to the bicylic cis-diol 3 in a stereospecific manner.
Synthesis and biological evaluation of A-ring analogs of the natural germination stimulant strigol
Mangnus, E. M.,Zwanenburg, B.
, p. 155 - 159 (2007/10/02)
An A-ring-derived analog of the natural germination stimulant, Strigol (1), has been prepared from citral in an unambiguous manner.This analog, 2, a γ-hydroxy aldehyde for which a high stimulant activity was claimed in the literature, has been re-evaluate
