Process for making intermediates for fragrance components from α-campholenic aldehyde
AssigneeMillennium Specialty Chemicals, Inc.
InventorsGennadiy G. Kolomeyer, Jacob Oyloe, Douglas A. Ferone
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Abstract
A two-step aldol condensation process is disclosed. α-Campholenic aldehyde (ACA) and methyl ethyl ketone (MEK) react in the presence of a base under conditions effective to produce a mixture comprising a high yield of ketol condensation products. Dehydration of the ketols in the presence of an organic sulfonic acid provides unsaturated ketones that are valuable intermediates for fragrance components for synthetic sandalwood products. Compared with the usual one-step, base-catalyzed approach, the two-step process increases the yield of all condensation products and maximizes production of the most valuable ketone isomers.
Claims16
A process which comprises reacting α-campholenic aldehyde (ACA) with methyl ethyl ketone (MEK) in the presence of a base comprising an aqueous alkali metal or alkaline earth metal hydroxide solution under conditions effective to produce a condensation product mixture comprising ketol A and ketone 1 having the structures:
- wherein the mixture comprises at least 60 wt. % of ketol A and at least 65 wt. % of ketol A and ketone 1 combined.
A process which comprises:
- (a) reacting ACA with MEK in the presence of a base comprising an alkali metal hydroxide solution under conditions effective to produce a condensation product mixture comprising ketol A and ketone 1 having the structures:
- wherein the mixture comprises at least 60 wt. % of ketol A and at least 65 wt. % of ketol A and ketone 1 combined;
- and
- (b) dehydrating the condensation product mixture in the presence of p-toluenesulfonic acid to produce a ketone-rich mixture comprising at least 70 wt. % of ketone 1.
Dependencies are inferred from the claim text.