P-Phenethyl alcohol

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). 

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). 

Benzyl alcohol (1) and P-phenethyl alcohol (2) (2-phenylethanol) are the simplest of the aromatic alcohols, and, as such, are chemically similar. Their physical properties are given in Table 1. 

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

Of all the aromatic organic molecules P-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. 

Nearly all of the benzyl chloride [100-44-7], henzal chloride [98-87-3], and hen zotrichl oride /P< -(97-i manufactured is converted to other chemical intermediates or products by reactions involving the chlorine substituents of the side chain. Each of the compounds has a single primary use that consumes a large portion of the compound produced. Benzyl chloride is utilized in the manufacture of benzyl butyl phthalate, a vinyl resin plasticizer benzal chloride is hydrolyzed to benzaldehyde hen zotrichl oride is converted to benzoyl chloride. Benzyl chloride is also hydrolyzed to benzyl alcohol, which is used in the photographic industry, in perfumes (as esters), and in peptide synthesis by conversion to benzyl chloroformate [501-53-1] (see Benzyl ALCOHOL AND p-PHENETHYL ALCOHOL CARBONIC AND CARBONOCm ORIDIC ESTERS). 

Uses. Used as an intermediate in the production of styrene glycol and its derivatives as a reactive dilutent in the epoxy resin industry as a chemical intermediate for making P-phenethyl alcohol, a fragrance material... 

Benzyl acetates react with trimethylsilane and CO in the presence of Co2(CO)8 as catalyst to give P-phenethyl alcohols by a one-carbon homologation. The active catalyst is assumed to be (CH3)3SiCo(CO)4. The reaction proceeds under CO at atmospheric pressure at 25°. It fails with benzyl alcohol itself, but is successful with benzyl formate and benzyl methyl ether.5... 

Finally, Section 8.5 discusses the design of chromatographic reactors, using as examples the esterification of P-phenethyl alcohol with acetic acid and the isomerization of glucose. 

P-Phenethyl acetate production from P-phenethyl alcohol and acetic acid is an example of an heterogeneously catalyzed esterification reaction ... 

Esterification of P-Phenethyl Alcohol with Acetic Acid 393... 

The ability to discriminate different molecules constitutes a criterion for olfaction. Because, as mentioned, anosmic persons can tell some pairs of odors apart based on nonolfactory cues, an experimenter must choose with care the compounds for study. 3-Phenethyl alcohol has an odor that many people find reminiscent of roses, and vapors from dilute solutions are widely accepted as an olfactory stimulus that does not interact with other chemosensory modalities in humans (Betcher Doty, 1998). Consider a human subject who can detect J3-phenethyl alcohol with the same sensitivity as nor-mosraics and can also detect -butanol (another alcohol often used for testing olfactory sensitivity (Hummel et al., 1997), which has an odor very different from that of P-phenethyl alcohol) with normal acuity. Suppose this subject cannot distinguish the two odors. How can an experimenter assess whether the subject exhibits the sense called olfaction ... 

Could one devise a strategy for differentiating -butanol from P-phenethyl alcohol using H. M. as a detector, without confounding odor quality with odor intensity An affirmative answer comes from H. M. s adaptation to odors. When H. M. sniffed n-butanol for a period of time, his experimentally measured sensitivity to both odors decreased, but adaptation attenuated his sensitivity to P-phenethyl alcohol much less than his sensitivity to n-butanol. Similarly, sniffing P-phenethyl alcohol for a period of time attenuated his sensitivity to that odorant (self adaptation) but did not affect his sensitivity to n-butanol significantly (no crossadaptation). The selectivity of his adaptation demonstrates that H. M. indeed uses olfaction to detect odors. Moreover, his adaptation (like that of normosmics) occurs in the CNS, as detailed in the following discussion. 

When P. D. sniffed a more concentrated solution of n-butanol in the opposite nostril, his one-nostril sensitivity decreased (symbolized by squares in fig. 14.1). But when he subsequently sniffed concentrated P-phenethyl alcohol in the opposite nostril, his sen-stivity was slightly greater than in the unadapted condition (symbolized by triangles). 

Thus, P. D. exhibited contralateral self adaptation to n-butanol without any crossadaptation to p-phenethyl alcohol. It was not possible to test H. M. as thoroughly as P. D., but, as figure 14.1 summarizes, his contralateral self adaptation to n-butanol did not differ signficantly from his bilateral self adaptation, and both were essentially the same as P. D. s contralateral self-adaptation. 

Let me relate a piece of anecdotal evidence that suggests the dependence of olfaction upon the way that odors arrive at the nose. One of my students had been a subject in numerous signal detection experiments using weak solutions of P-phenethyl alcohol in water as a stimulus, in which she was inhaling its vapors in a continuous... 

The chromatographic SMB reactor has been examined for various reaction stoichiometries, with the main focus on reactions of the type A + B C + D. Examples are esterifications of acetic acid with methanol (Lode et al., 2003 Strohlein, Mazzotti, and Morbidelli, 2005), ethanol (Mazzotti et al, 1996), and p -phenethyl alcohol (Kawase et al, 1996) as well as the production of bisphenol A (Kawase ef al, 1999). The same reaction type can also be found for various hydrocarbons, such as the transfer reaction of sucrose with lactose to lactosucrose (Kawase ef al, 2001) and the hydrolysis of lactose (Shieh and Barker, 1996). Barker ef al (1992), Kurup ef al (2004) and Strohlein, Mazzotti, and Morbidelli (2005) focused on reactions of the type A B + C, such as enzyme-catalyzed sucrose inversion and the production of dextran. 

Phenethyl alcohol p-Phenethyl alcohol 2-Phenylethanol p-Phenylethanol Phenylethyl alcohol... 

P-Phenethyl alcohol. See Phenethyl alcohol s-Phenethyl alcohol. See a-Methylbenzyl alcohol... 

Ringk, W., Theimer, E.T. Benzyl Alcohol and P-Phenethyl Alcohol In Kirk-Othmer, Encycl. Chem. Tech., 3. Ed., 3, 793 (1978)... 

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