The selective O-acylation of enolates providing a simple entry to O-enesters
In the presence of catalytic amounts of a fluoride source, O-trimethylsilyl enethers undergo condensation with acyl fluorides to afford O-enesters with high yields. The intermediates and final products are pure (Z) isomers if only one double bond is in conjugation with the oxygen atom whereas (E) isomers prevail if silyl dienethers or trienethers and O-trienesters are formed.
METHOD FOR SEPARATING HIGH-BOILING CARBOXYLIC ACID VINYL ESTER/CARBOXYLIC ACID MIXTURES
The invention relates to a method for separating a mixture containing at least one carboxylic acid vinyl ester of general formula R′—C(O)O—CH═CH2 and at least one carboxylic acid of general formula R′—COOH, wherein R′ in either case can be an aliphatic group having 12 to 22 C atoms or a cycloaliphatic group having 12 to 22 C atoms, or an aromatic group having 12 to 22 C atoms, and R′ can be identical or different, characterized in that the carboxylic acid is converted to its anhydride R′—C(O)—O—C(O)—R′ and the carboxylic acid vinyl ester is subsequently separated.