Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Patent
1997-11-05
1999-02-23
Shippen, Michael L.
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
568700, 568840, 568799, 568875, 568881, C07C 3506
Patent
active
058746498
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for preparing an unsaturated alcohol, preferably to a process to efficiently prepare an unsaturated alcohol by selectively reducing the aldehyde group of an .alpha.,.beta.-unsaturated aldehyde compound.
2. Description of Related Art
For preparing the unsaturated alcohols, a process is known, wherein the aldehyde group of an .alpha.,.beta.-unsaturated aldehyde compound is selectively reduced. Particularly, an unsaturated alcohol having 2,2,3-trimethyl-3-cyclopenten-1-yl group represented by the formula (I): ##STR2## is known to be a perfume having musk-like smell as well as sandalwood-like smell, and prepared by selectively reducing the aldehyde group alone of an .alpha.,.beta.-unsaturated aldehyde compound having 2,2,3-trimethyl-3-cyclopenten-1-yl group represented by the above formula (I).
For example, JP-B 56-36176 discloses a process for preparing 2-methyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol represented by the formula (III'): ##STR3## by selectively reducing the aldehyde group alone of 2-methyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-al represented by the formula (II'): ##STR4## using aluminum alcoholate or a metal hydride compound in the presence of isopropyl alcohol.
This method, however, utilizes a large amount of aluminum alcoholate or a metal hydride compound as much as 40 mol % of the aldehyde as the starting material, as well as a large excess of isopropyl alcohol, i.e., more than 20 times by mole the amount of the aldehyde as the starting material, that is, this method is not efficient with low productivity.
DISCLOSURE OF THE INVENTION
An object of the present invention is to provide a process for efficient preparing an unsaturated alcohol from an .alpha.,.beta.-unsaturated aldehyde compound.
The present inventors have studied intensively to solve the above problems and, as the results, have attained the present invention.
That is, the present invention provides a process for preparing an unsaturated alcohol from an .alpha.,.beta.-unsaturated aldehyde compound using an aluminum alcoholate in the presence of a primary or secondary alcohol having 2 to 8 carbon atoms by selective reduction of the aldehyde group, wherein the reaction is carried out with addition of a protonic acid.
In other words, the present invention provides a process for preparing of an unsaturated alcohol by selective reduction of the aldehyde group of an .alpha.,.beta.-unsaturated aldehyde compound in the presence of a primary or secondary alcohol having 2 to 8 carbon atoms, an aluminum alcoholate and a protonic acid.
DETAILED DESCRIPTION OF THE INVENTION
The mode for carrying out the present invention will be illustrated in detail.
Preferably, the present invention is a process for preparing an unsaturated alcohol by selectively reducing the aldehyde group of an .alpha.,.beta.-unsaturated aldehyde compound in the presence of 0.7 to 15 times by mole of the amount of the primary or secondary alcohol having 2 to 8 carbon atoms, 0.5 to 35 mol % of the aluminum alcoholate and 0.005 to 30 mol % of the protonic acid, based on the .alpha.,.beta.-unsaturated aldehyde compound.
The .alpha.,.beta.-unsaturated aldehyde used in the present invention is not particularly limited so long as it may be an aldehyde having an unsaturated bond at .alpha.,.beta.-position of the aldehyde group. Typical examples include compounds having 2,2,3-trimethyl-3-cyclopenten-1-yl group represented by the above formula (I).
The process according to the present invention may be preferably applied to the reaction to obtain 2-alkyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-ol represented by the formula (III): ##STR5## (wherein R represents an alkyl group having 1 to 3 carbon atoms) utilizing 2-alkyl-4-(2,2,3-trimethyl-3-cyclopenten-1-yl)-2-buten-1-al represented by the formula (II): ##STR6## (wherein R is defined as above) as the .alpha.,.beta.-unsaturated aldehyde.
In the above formulae (II) and (III), R represents an alkyl gro
Koshino Junji
Kotachi Shinji
Tanaka Shigeyoshi
Yamamoto Junko
Kao Corporation
Shippen Michael L.
LandOfFree
Process for preparing unsaturated alcohol does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for preparing unsaturated alcohol, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for preparing unsaturated alcohol will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-309044