Diastereoselective method of preparing olefins by means of the horner-wadsworthemmons reaction, comprising the addition of a tris-(polyoxaalkyl)-amine sequestering agent

摘要

The invention relates to a process for the diastereoselective preparation of olefins via the Homer-Wadsworth-Emmons reaction, which consists in reacting at low temperature a phosphonate with a carbonyl derivative in the presence of a base in a suitable solvent, characterized in that a tris(polyoxaalkyl)amine sequestering reagent of formula (I): N—[CHR₁—CHR₂—O—(CHR₃—CHR₄—O)_n—R₅]₃ (I), wherein: n is an integer between 0 and 10; R₁, R₂, R₃ and R₄ may be identical or different, and represent a hydrogen atom or an alkyl radical containing from 1 to 4 carbon atoms; R₅ represents a hydrogen atom, an alkyl or cycloalkyl radical containing up to 12 carbon atoms, a phenyl radical or a radical of formula —CμH2μ-Φ, or C_mH_2m+1-Φ-, with m being an integer between 1 and 12 and Φ being a phenyl radical; is added in an amount that is sufficient to increase the diastereoselectivity of the olefin.