Process for the preparation of carboxylic acid esters of .beta.-formyl-crotyl alcohol by an allyl rearrangement
US4301084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 31, 1979 |
| Grant date | Nov 17, 1981 |
| Priority date | — |
| Expiry date | Aug 31, 1999 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07C67/29
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
In a process for the preparation of a carboxylic acid ester of .beta.-formyl-crotyl alcohol by rearrangement of the corresponding carboxylic acid ester of 2-formyl-2-hydroxy-but-3-ene or of an acetal or acylate thereof in the presence of copper or a copper compound, followed, where relevant, by hydrolytic cleavage of the acetal or acylate, more especially in the preparation of 4,4-dimethoxy-3-methyl-crotyl acetate, the yield is improved by carrying out the rearrangement in the presence of copper (I) chloride as the catalyst and ensuring that low-boiling by-products formed during the rearrangement are removed. The products are of great importance as starting materials for an industrial synthesis of vitamin A and its derivatives.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.