DIENEDIOLATES OF UNSATURATED CARBOXYLIC-ACIDS IN SYNTHESIS - ALDEHYDES AND KETONES FROM ALKYL-HALIDES, BY OZONOLYSIS OF BETA,GAMMA-UNSATURATED ALPHA-ALKYL CARBOXYLIC-ACIDS - THE ROLE OF A TERTIARY AMINE IN THECLEAVAGE OF OZONIDES

A convenient two-step procedure for a two carbon homologative conversi on of alkyl halides into aldehydes and methyl ketones by alpha-alkylat ion of unsaturated carboxylic acids, followed by ozonolysis is develop ed and applied to the synthesis of omega-chloro aldehydes. Triethylami ne is superior to dimethyl sulfide or triphenylphosphine for cleavage of the ozonides, except when aldol condensation side reactions require use of protic solvents and iodide salts. Cleavage of the ozonides by triethylamine is shown to occur mainly through a reductive process. (C ) 1997 Elsevier Science Ltd.