Perfume Materials: The Addition of Acetic Acid and Allylalcohol to Dicyclopentadiene

Leitmannová et al. investigated the effect of reaction conditions on addition of carboxylic acids (acetic and propionic) and alcohols (allylalcohol) to dicyclopentadiene. The effect of temperature, an excess of carboxylic acid or alcohol and the catalyst amount, as well as the effect of the presence of water in the case of the addition of carboxylic acids were monitored. The catalyst applied in the case of the addition of acids to dicyclopentadiene was sulfuric acid, and methanesulphonic acid in the case of the allylalcohol addition. Acquired optimal conditions were verified via preparative experiments with yields around 88 percent. The products of carboxylic acid additions to dicyclopentadiene were further hydrogenated. During hydrogenation, the effect of temperature and the catalyst amount (Ni/Al2O3) was monitored. All acquired products have use in the perfume industry.

Introduction

The addition of alcohols and carboxylic acids to dicyclopentadiene (DCPD) proceeds in the presence of acidic catalysts and produces relevant ethers and esters of dicyclopentadiene:

Two different ways of preparation of the given compounds are known. During the first, carboxylic acid reacts with hydroxydihydrodicyclopentadiene or alcoholate of an alkali metal with dicyclopentadienyl halide. The second method consists in an electrophilic addition of an alcohol or acid to DCPD in the presence of an acid catalyst (a different reactivity of double bonds in DCPD is beneficially utilized).

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