Diels-alder reaction of aldehydes with simple dienes
US6114548A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 19, 1998 |
| Grant date | Sep 5, 2000 |
| Priority date | — |
| Expiry date | Jan 19, 2018 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC07D309/20
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The invention concerns Diels-Alder reactions between non-activated aldehydes RCHO in which R is a C1-C10 aliphatic group or phenyl group, which is unsubstituted or substituted with one or more C1-C5 alkyl groups or one other functional group, with simple aliphatic dienes R.sub.1 CH.dbd.CR.sub.2 --CR.sub.3 .dbd.CHR.sub.4 in which R.sub.1 -R.sub.4 are H or C1-C5 alkyl groups using as a catalyst a perfluorinated organic sulphonic acid or a Bronsted acid derivative thereof. The reaction leads to dihydropyrans of the structure below in which R1-R4 have the meaning indicated above. The preferred perfluorinated organic sulfonic acids are perfluorooctanesulphonic acid, triflic acid, Nafion or a Bronsted acid derivative of triflic acid. ##STR1## The preferred aldehydes are those wherein R is a C2-C6 aliphatic group or a phenyl group which is unsubstituted or mono-substituted with C1-C3 alkyl or with 4-Cl, 4-nitro or 3-methoxy. The preferred dienes are those wherein the groups R.sub.1 -R.sub.4 are H or methyl.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.