Лако-красочные материалы — производство

2-Methylhept-2-en-6-one, usually referred to simply as methylhep — tenone, is a useful synthon for the total synthesis of terpenes. One early synthesis of this intermediate employed the Carroll reaction, the substrate for which is prepared by the addition of acetylene to acetone and subsequent partial hydrogenation to 2-methylbut-3-en-2-ol, as shown in Scheme 4.5. Addition of […]

Hydrogenation of the less expensive a-pinene gives pinane, which can be oxidized by air under radical conditions to give the hydroperoxide, which is then reduced to pinan-2-ol. Pyrolysis of this alcohol gives linalool, as shown in Scheme 4.3. This process is operated by Glidco at their plant in Georgia in the USA. The disadvantage of […]

One of the earliest commercial routes into this key group of terpenes involved pyrolysis of Д-pinene, as shown in Scheme 4.2. When ^-pinene is heated to 500 °С, the cyclobutane ring breaks via a retro-2 + 2 cycloaddition. This ring opening is regioselective and produces the triene, myrcene. Addition of hydrogen chloride to myrcene gives […]

As mentioned above, routes to the major synthetic terpenes start from either turpentine or petrochemical sources. When softwood (pine, fir, spruce) is converted into pulp in the Krafft paper process, the water-insoluble liquids which were present in it are freed and can be removed by physical separation from the process water. This material is known […]

Geraniol-nerol, linalool, citronellol, citronellal and citral are five of the most important terpenes as far as the perfume industry is concerned. Apart from citral, all are used as such in perfumes, and the alcohols and their esters are particularly important. All of them are key starting materials for other terpenes, as discussed later. Scheme 4.1 […]

Introduction The terpenes form the largest group of natural odorants, so it is only to be expected that they also form the largest group of modern fragrance ingredients. Thousands of different terpene structures occur in perfume ingredi­ents, both natural and synthetic. The chemistry of terpenes is rich and varied and attempts to understand it have, […]

CHARLES SELL ECONOMIC FACTORS AFFECTING PERFUMEINGREDIENT PRODUCTION The four main factors that affect the volume of use of a fragrance ingredient are its odour contribution to a fragrance, its stability and performance in the products to be perfumed, its safety in use and its cost. The first three factors are discussed in the chapters on […]

Until the middle of the nineteenth century, perfumes were largely for personal application and, furthermore, that use was restricted mostly to the wealthiest strata of society because of the cost of producing the natural materials required as ingredients. The development of organic chemistry in the nineteenth century began to make synthetic chemicals available and their […]

The high prices that essential oils command lead, inevitably, to the temptation for less scrupulous producers and dealers to adulterate the product. Adulteration is sometimes referred to, euphemistically, as sophistication. By adding lower cost materials, but still asking the same high price for the mixture, the person perpetrating the fraud can stand to make considerable […]

Scheme 3.9 summarizes the various possible processes using solvent extraction to obtain perfume ingredients. The processes are written in lower case and the technical names for the various products in capitals.