Process for the preparation of polyendialdehydemonoacetals

摘要

Production of polyene dialdehyde monoacetals (I) involves, reacting a dialdehyde monoacetal (II) with a Wittig or Wittig-Horner reagent (III) to give an acid ester acetal compound (IV), optionally converting the product into an acid ester acetal compound (IV) by hydrolysis and reaction with a Wittig or Wittig-Horner reagent (V), reducing (IV) to an alcohol (VII) and (d) oxidizing (VII) to (I). Production of polyene dialdehyde monoacetals of formula (I) involves: (i) reacting a dialdehyde monoacetal of formula (II) with a Wittig or Wittig-Horner reagent of formula (III) to give an ester-acetal compound of formula (IV; k = 0); (ii) optionally converting (IV; k = 0) into a higher ester-acetal compound of formula (IV; k = 1) by hydrolysis of the acetal function and reaction with a Wittig or Wittig-Horner reagent of formula (V); (iii) reducing (IV) to an alcohol of formula (VII); and (iv) oxidizing (VII) to (I). R1, R2 = 1-8C alkyl or -CH(OR1)(OR2) = dioxan or dioxolan group of formula (i) or (ii); R3 - R5 = H or 1-4C alkyl; R6 = 1-6C alkyl; P' = triarylphosphonium or phosphonic acid dialkyl ester residue; and k = 0 or 1. Independent claims are included for: (1) the intermediates (IV) (provided that R5 is not H if k = 0 and R = Me) and (VII) as new compounds; and (2) the products (I) as new compounds (provided that R3 and R4 are not both Me).