Process for the preparation of cycloaliphatic aldehydes
AssigneeFirmenich SA
InventorsCharles Fehr, Jose Galindo
Life of this patent
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Abstract
Process for the preparation of cycloaliphatic aldehydes of formula ##STR1## having either an isolated double bond in position 1 or 2 (endocyclic or exocyclic), or two conjugated double bonds in position 1 and 3 or 2(exocyclic) and 3 of the ring as indicated by the dotted lines, which process consists in subjecting to a deprotonation an ester of formula ##STR2## wherein the dotted lines have the above given meaning and Y designates an oxygen atom or a sulphur atom and R' stands for a linear or branched alkyl radical or a substituted or unsubstituted phenyl group, followed by H.sup..crclbar. addition and hydrolysis.
Claims8
Process for the preparation of cycloaliphatic aldehydes of formula ##STR14## having either an isolated double bond in position 1 or 2 (endocyclic or exocyclic) or two conjugated double bonds in position 1 and 3 or 2(exocyclic) and 3 of the ring as indicated by the dotted lines, which comprises the following subsequent reaction steps:
- a. deprotonation of an ester of formula ##STR15## wherein the dotted lines have the above given meaning, symbol Y designates an oxygen or sulphur atom and R' represents a linear or branched alkyl radical or a phenyl radical;
- b. addition to the thus formed enolate or formula ##STR16## of a reducing agent capable to generate H.sup..crclbar. anions in the reaction conditions, followed optionally by the treatment of the obtained product with a trialkyl-silyl halide;
- and
- c. hydrolysis of the resulting product.
Dependencies are inferred from the claim text.