Process for the oxidation of primary allylic alcohols
AssigneeSCM Corporation
InventorWilliam J. Ehmann
Life of this patent
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Abstract
Improved conversions of 3-substituted and 3,3-disubstituted allyl alcohols to the corresponding aldehydes are obtained in an Oppenauer oxidation process, under Oppenauer oxidation conditions, by carrying out the oxidation employing furfural as the hydrogen acceptor. The invention is particularly applicable to the oxidation of geraniol and nerol to citral, which can be converted directly to pseudoionone without purification.
Claims13
In an Oppenauer oxidation for converting a 3-substituted or 3,3-disubstituted allyl alcohol having the following configuration ##STR6## wherein R is an aliphatic or aromatic group and R' is hydrogen, an aliphatic or an aromatic group, into the corresponding olefin aldehyde, in the presence of an Oppenauer oxidation catalyst and hydrogen acceptor under mild temperature Oppenauer oxidation conditions, the improvement which comprises carrying out said oxidation in the presence of furfural as said hydrogen acceptor in a molar ratio of furfural to allyl alcohol of about 10:1-1:10 and forming a reaction product mixture containing the aldehyde corresponding to the allyl alcohol and as a by-product, furfuryl alcohol, said catalyst being employed in a catalytic amount.
In an Oppenauer oxidation for converting a 3-substituted or 3,3-disubstituted allyl alcohol selected from the group consisting of nerol/geraniol (3,7-dimethyl-2,6-octadien-1-ol), prenol (3-methyl-2-butene-1-ol), farnesol (3,7,11-trimethyl-2,6,10-dodecatrien-1-ol), cinnamyl alcohol (C.sub.6 H.sub.5 CH=CHCH.sub.2 OH) and 2-hexen-1-ol, into the corresponding olefin aldehyde in the presence of an Oppenauer oxidation catalyst and hydrogen acceptor under mild temperature Oppenauer oxidation conditions, the improvement which comprises carrying out said oxidation in the presence of furfural as said hydrogen acceptor in a molar ratio of furfural to alcohol of about 10:1-1:10 and forming a reaction product mixture containing the aldehyde corresponding to the allyl alcohol and as a by-product, furfuryl alcohol, said catalyst being employed in a catalytic amount.
Dependencies are inferred from the claim text.