Method for synthesizing methyl heptenone from methyl butynol

Abstract

The invention provides a method for synthesizing methyl heptenone from methyl butynolwhich. The method comprises the following steps: carrying out a rearrangement reaction on methyl butynol and 2-alkoxy propylene under the action of an acid catalyst to obtain a mixture of allenyl ketone and methylheptadienone; and carrying out selective hydrogenation on the mixture under the action of a hydrogenation catalyst to obtain the methyl heptenone product. The synthesis route is novel, firstly, the rearrangement reaction is firstly carried out to obtain allenyl ketone and methylheptadienone intermediates, and the problem of low selectivity of enol synthesis by alkynol hydrogenation is avoided; sulfonic acid resin and a Lewis acid are used for a synergistic catalytic reaction, so that the rearrangement reaction condition is mild; then hydrogenation of allenyl ketone and methylheptadienone is catalyzed by using a Lindelar catalyst and taking an alkali and quinoline as assistants so as to obtainthe methyl heptenone with high selectivity; and the method has the advantages of readily available starting raw materials, low price, high total yield of the route, good cost advantage and potential application prospect.

Description

technical field [0001] The invention belongs to the fields of fine chemicals and flavors and fragrances, and in particular relates to a method for rapidly and efficiently synthesizing methyl heptenone from methyl butynol through rearrangement and hydrogenation reactions. Background technique [0002] γ, δ-unsaturated ketones widely exist in natural products and fine chemicals, such as methyl heptenone, which has a fresh fruit aroma and is a food flavor allowed by the national standard of our country. At the same time, methyl heptenone is still important It can be used to synthesize linalool, linalyl acetate, vitamin A and vitamin E and other fine chemical products with great economic value. Based on the important application of methyl heptenone, people have developed a number of different synthetic routes of methyl heptenone, mainly acetylene-acetone method (DE2126356, GB788301, GB888999, DE1137433), isobutylene-formaldehyde method (DE1277848B, DE1267682B ) and the isoprene...

AI Technical Summary

Problems solved by technology

At present, the better partial hydrogenation reaction selectivity is basically between 90-95%, and cannot reach 100% chemoselectivity

At the same time, the slow reaction rate also limits the space-time yield of the reactor, resulting in low production efficiency

[0006] To sum up, at present, the acetylene propargone method is one of the economically feasible routes for synthesizing methylheptenone, but the main problem of this synthetic route is that methylbutyne Partial hydrogenation of alcohols to synthesize methyl butenol, due to the high similarity in the functional groups of acetylene alcohols and enols, it is difficult to perfectly control the selectivity of the partial hydrogenation reaction

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