Hydroxycitronellal

Hydration of (R,E)-diethylenamine, followed by hydrolysis with sulfuric acid gives (+)-7-hydroxycitronellal, which is known as an artificial perfume with pleasant olfactory properties, with high optical purity (Scheme 5).9... 

Citric acid activity (CAA) test, 15 405 Citric acid cycle, 6 632-633 Citrine, color, 7 337 Citrogypsum, 4 593 Citronella, 24 504 Citronellal, 3 232 24 532-533 hydration to hydroxycitronellal,... 

Hydroxy-cis-9-octadecenoic (ricinoleic) acid, physical properties, 5 35t 14-Hydroxy-cis-ll-eicosenoic (lesquerolic) acid, physical properties, 5 35t Hydroxycitronellal, 24 489, 490, 533—534 Hydroxy-containing organics, 20 794-795 3-Hydroxycyclohexanecarboxylic acid, 22 21... 

Uses and Reactions. The largest use of myrcene is for the production of the terpene alcohols nerol, geraniol, and linalool. The nerol and geraniol are further used as intermediates for the production of other latge-volume flavor and fragrance chemicals such as citronellol, dimethyloctanol, citronellal, hydroxycitronellal, racemic menthol, citral, and the ionones and methylionones. 

Epoxidation of dihydromyrcenol gives an intermediate epoxide that can be hydrogenated to hydroxycitronellol. Treatment of the diol with acid can also give the a-,P-citronellol and the a-citronellol can be isomerized to the P-citronellol (27) (110). The diol, hydroxycitronellol, is also useful for producing hydroxycitronellal, a lily-of-the-valley fragrance material. 

Uses and Reactions. The main use for citronellol is for use in soaps, deteigents, and other household products. It is also important as an intermediate in the synthesis of other important fragrance compounds, such as citronellyl acetate and other esters, citronellal, hydroxycitronellal, and menthol. 

Flowery Anisyl alcohol Benzyl acetate, phenylaceiate Cinnamic acid Cinnamyl acetate Citronellyl formate Crcsyl acetate Decanal Dimethyl benzyl carbinol Dimethyl benzyl carbinyl acetate Ethyl anthranilate Geranyl acetate Hydroxycitronellal dimethyl acetate Linalool Linalyl acetate Methyl benzoate Pcnethyl acetate 2-Phcnylpropionaldehyde 3-Phenylpropionaldehvde. 

Hydroformylation of 2,6-dimethyl-6-hepten-2-ol produces hydroxycitronellal (equation 12).22 Subjecting allyl alcohol to hydroformylation reaction conditions with HCo(CO>4 yields only propanal, isomerization taking place more rapidly than hydroformylation.2 Phosphine-modified rhodium catalysts will convert allyl alcohol to butane-1,4-diol under mild conditions in the presence of excess phosphine, however (equation 13).5 30 31 When isomerization is blocked, hydroformylation proceeds normally (equation 14). An elegant synthesis of the Prelog-Djerassi lactone has been accomplished starting with the hydroformylation of an allylic alcohol (equation IS).32... 

HYDROXYCITRONELLAL, TERPINEOL LINALOOL, PHENYLETHYL ALCOHOL, ANISIC ALCOHOL,... 

Terpenoid alcohols appeared early in the history of synthetic perfumery because several were readily available from inexpensive essential oils. Alpha-terpineol, citronellol and linalool shown in Figure 7 are important constituents of pine stump oil, citro-nella oil and rosewood oil, respectively. The fourth material listed, hydroxycitronellal, is a hydroxy aldehyde which perhaps has a questionable place in this discussion. It is included because it is one of the most important fragrance chemicals used today. "Hydroxy" is almost a perfume unto itself. Its soft flowery, linden blossom odor blends very well in many floral perfumes. 

Many floral notes overlap in the types of material from which they can be made. The same eight materials—phenylethyl alcohol, hydroxycitronellal, benzyl acetate, phenylactaldehyde, citronellol, hexyl cinnamic aldehyde, terpineol, and indol—mixed together in different proportions can produce either a jasmin, a lilac, a muguet, or a hyacinth. The list also includes three materials that occur in nearly all rose compounds. If used together in a formula, bases that contain only... 

Phenylethyl acetate Hydroxycitronellal Phenylethyl butyrate Phenoxyethyl isobutyrate... 

Initially, at the beginning of the present century, the traditional structure of the earlier perfumes was for the most part retained. "Fresh" natural materials such as bergamot and lemon, in combination with other essential oils, formed a large proportion of the composition, supported by animal and balsamic fixatives. To these were added the newly discovered synthetic and derived materials such as vanillin, coumarin, hydroxycitronellal, vetiveryl acetate, and methyl ionone, to-... 

Another technique much used in the past, though less popular today, was to take well-known products such as methyl ionone, vetiveryl acetate, or hydroxycitronellal—materials that themselves could often form 10-20% of a finished perfume—and decorate them with a number of other synthetic and natural materials to form a base with much of the complexity and "roundness of a finished perfume. Many such bases, for example, Althenol and Selvone (used in Ma Griffe), were created by Carles to be used not only by himself but also by client perfumers who lacked perhaps the same level of technical proficiency. 

The middle part of the perfume is a bouquet of floral notes reduced to their simplest components. Terpineol for lilac, styrallyl acetate for gardenia, phenylethyl alcohol for rose, hydroxycitronellal (10%) for muguet, and benzyl acetate and amyl cinnamic aldehyde for jasmin. 

Among the most important of these structural differences are the introduction of cis-3-hexenyl salicylate (6%) replacing part of the benzyl salicylate, and the replacement of hydroxycitronellal by Lyral (8%). Both changes are in keeping with the green, floral direction of the perfume. The woody and musk notes have also been modified and augmented by the introduction of newer materials such as Vertofix (3%) and ambrettolide. 

The green side of the perfume which is less pronounced than in Fidji, and more floral, is based on phenylacetaldehyde and cA-3-hexenyl acetate with perhaps a trace of galbanum. Narcisse absolute may also be used. Other materials that add to the building up of the white flower character are Lilial and cyclamen aldehyde in addition to the hydroxycitronellal and Lyral. The tuberose character can be given by the use of the Schiff base derived from methyl anthranilate and Helional, or by the direct addition of methyl anthranilate. The mossy side of the perfume is represented by Evemyl. 

As we would expect in a perfume as distantly related in time as Opium is to both Shalimar and Youth Dew, a number of more modem materials have been introduced. The cis-3-hexenyl salicylate backs up the benzyl salicylate, and Lyral, the hydroxycitronellal. A small amount of Hedione is also included. There have been important developments to the rose aspect of the perfume with the addition of phenylethyl dimethyl carbinol (3%) and Centifolyl. The fresh character of the rose derives from the use of geranyl acetate. Unlike the earlier oriental perfumes there is also an important aldehydic note. 

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