Alcohols phenethyl

BENZYL ALCOHOL AND /J-PHENETHYL ALCOHOL. Benzyl alcohol [CAS 100-51-6], (1) /1-phenethyl alcohol (2) (2-phenylethauol) are the simplest of the aromatic alcohols, and. as such, are chemically similar. Their physical properties are given in Table I. 

Of all die aromatic organic molecules /1-phenethyl alcohol (PEA) (2) is probably the most prestigious aroma chemical in the world of perfumery. This is because of its exquisite odor of natural rose petals. 

Carboxylic acids can be converted directly to the dithioic acid esters on treatment with a thiol and 20 mol% of P4S10 (Entry 6) [31 ]. It has been proposed that this reaction involves the formation of the 0-aroyl (or acyl) trithiophosphate derivative 20, the reaction of these intermediates with thiols, and thionation of the resulting S-substituted thioates with P4S10. Alcohols such as benzyl alcohol, t-butyl alcohol, 1-phenethyl alcohol were used instead of thiols it was claimed that these alcohols are initially converted to the corresponding thiols on reaction with P4S10 (Eq. 10) [31]. 

Finally, by using a chiral tertiary amine as the base, it is possible to effect enantioselective acetylations. For example, racemic 1-phenethyl alcohol has been partially resolved by treatment with AcCl in combination with (5)-(—)-/V,/V-dimethyl-l-phenethylamine (CH2CI2, —78 °C -> rt ee of acetate 52%, ee of alcohol 59.5%). ... 

PEA from pENZYL ALCOHOL AND BETA-PHENETHYL ALCOHOL] (Vol 4)... 

Other commonly occurring chemical groups ia essential oils iaclude aromatics such as P-phenethyl alcohol, eugenol, vanillin, ben2aldehyde, cinnamaldehyde, etc heterocycHcs such as iadole (qv), pyra2iaes, thia2oles, etc hydrocarbons (Liaear, branched, saturated, or unsaturated) oxygenated compounds such as alcohols, acids, aldehydes, ketones, ethers and macrocyclic compounds such as the macrocyclic musks, which can be both saturated and unsaturated. 

Of all these, probably P-phenethyl alcohol (2) comes closest to the odor of fresh rose petals however, mixing all these components does not reproduce the total fine character of the natural oil. It has been determined that a number of trace constituents representing less than 1% of the volatiles are critical to the development of the complete rose fragrance (10). These include cis- and trans-i.ose oxide (1), nerol oxide (12), rose furan (13), /)i7n7-menth-l-en-9-al (14), P-ionone (15), P-damascone (16), and P-damascenone (3). 

Rose. Rose is one of the most important florals ia perfumery, the most valuable derivatives of which are produced from Rosa damascena, which is grown principally ia Bulgaria, but also ia Russia, Turkey, Syria, India, and Morocco. The concrete, absolute, and steam-distilled essential oil (rose otto) are particularly valuable perfume iagredients. Careful handling and processiag of freshly picked flowers are required to produce these materials of warm, deeply floral, and rich odor quaUty. They are complex mixtures of which citroneUol (9), geraniol (8), phenethyl alcohol [60-12-8] (21), and P-damascenone [23726-93 ] (22) (trace component) are important odor constituents. 

Benzyl alcohol, [100-51 -6] C H CH20H (bp, 205.4°C at 101.3 kPa), produced by the hydrogenation of benzaldehyde is used in color photography as a parenteral solution preservative as a general solvent and as an intermediate in the manufacture of various benzoate esters for the soap, perfume, and flavor industries (see Benzyl alcohol and P-phenethyl alcohol). 

Table 1. Physical Properties of Benzyl Alcohol and p-Phenethyl Alcohol...

Phenethyl alcohol may be identified as the phenethyl -nitrobenzoate [57455-00-2] (mp 106—108°C), as phenethyl -nitrobenzyl phthalate [65997-34-4] (mp 84.3°C), and also by its formation of styrene on treatment with alkaU. Use of these derivatives has, however, been superseded by physical methods. Infrared (75,76), mass spectroscopy (77), and nmr spectra (78) are useful for identification. 

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