Production of alkenones

摘要

A process for the production of alkenones (I) comprises reaction of an acid anhydride or acid halide with a vinyl ether in the presence of an onium salt of a carboxylic acid, or a one-two 1-3C alkyl substituted, optionally chlorinated pyridine or an onium salt of an inorganic acid. A process for the production of alkenones of formula (I) comprises reaction of an acid anhydride or acid halide of formula (II) with a vinyl ether of formula (III) in the presence of an onium salt of a carboxylic acid, or a one-two 1-3C alkyl substituted, optionally chlorinated pyridine or an onium salt of an inorganic acid. [Image] R 1>1-4C alkyl, optionally substituted by at least one halogen or CF 3C(O)CH 2; R 2>optionally substituted aryl or 1-4C alkyl, optionally substituted by at least one halogen; and X : R 1>-C(O)-O-, F, Cl or Br. Independent claims are also included for: (1) Adducts of a carboxylic acid anion of formula (IV) with a protonated cation of pyridine, substituted by one to three 1-3C alkyl groups, optionally chlorinated whereby the adduct optionally contains 0-2 moles of free acid per mole of adduct; and (2) Picolinium trilfuoroacetate derivative of formula (V). [Image] A : picolinium trifluoroacetate; B : trilfuoroacetic acid; and n : 0-2.