54827-25-7Relevant articles and documents
Aldolisation dirigee avec l'acroleine. Methode de synthese stereoselective de doubles liaisons trisubstituees fonctionnalisees. Application a la synthese du (+/-)-Z-chloronuciferal et du (+/-)-E-nuciferol
Depezay, Jean-Claude,Merrer Le, Yves
, p. 306 - 312 (2007/10/02)
To direct the aldolisation reaction in such a way that an aldehyde reacts upon the electrophilic carbonyl group of a ketone or of another aldehyde, it is necessary to mask the aldehyde and to transform it into a nucleophile.The present article presents an approach to this problem concerning unsaturated aldehydes and describes the condensation between the α-carbanion of acrolein and several carbonyl compounds. Aldol condensation at -70 degC, between 1,1-diethoxy-2-lithio-2-propene and several aldehydes leads to β-hydroxy-α-methylene acetals.These secondary allylic alcohols are stereoselectively transformed into trisubstituted functionalised olefinic compounds (Z-α-chlormethyl-α,β-unsaturated aldehydes and E-α-methyl-α,β-unsaturated primary alcohols). This method is illustrated by the syntheses of (+/-)-Z-chloronuciferal and (+/-)-E-nuciferol.