10-Methyl dodecanol

Chemical examination of the sea cucumber Holothuria leucospilota led to the isolation of a phytosphingosine-type glucocerebroside (40) with a 2-hydroxylated fatty acid of 22 carbons and an anteiso type side chain in the base moiety (Fig. 12) [55]. The absolute configuration of the branched methyl group was determined by release of a C13 fragment of the native cere-broside and further reduction to 10-methyl dodecanol. The absolute configuration of the natural alcohol was elucidated by comparison with synthetic optically active 10-methyl dodecanol synthesized from 1,4-butanediol [56]. 

In a i-l. three-necked flask fitted with a fetirrer and thermometer are placed 93 g. (0.5 mole) of dodecanol (Note 1) and 158 g. (2 moles) of pyridine. The flask is surrounded by a water bath sufficiently cold to lower the temperature of the mixture to io°. At this temperature 105 g. (0.55 mole) of />-toluenesul-fonyl chloride is added in portions over a twenty- to thirty-minute period, or at such a rate that the temperature does not exceed 20° at any time. The mixture is then stirred for three hours at a temperature below 20°, after which it is diluted with 300 cc. of hydrochloric acid (sp.gr. 1.19) in 11. of ice water. The ester which crystallizes is collected on a chilled Buchner funnel and sucked as dry as possible. The solid is transferred to a 600-cc. beaker, 250--300 cc. of methyl alcohol is added, and the mixture is warmed on the steam bath until the ester melts. It is then cooled in a freezing mixture while being stirred continuously the ester separates in a fairly fine state. It is then collected on a chilled funnel and allowed to dry in the air, preferably at a temperature, below 20°. The yield of ester is 152-156 g. (88-90 per cent of the theoretical amount based upon the dodecanol used). It melts at 20-250 (Note 2) and is sufficiently pure for most purposes. 

R) and (S)-3-octanol, (i )-2-dodecanol, (i )-2-methyl-4-heptanol and (i )-2-methyl-4-octanol, the pheromones of Myrmica scabrinodis, Crematogaster castanea, C. liengmei, C. auberti and Metamasius hemipterus were synthesized starting from nonracemic P-hydroxy sulfides. 

One further application is the synthesis of (S)-l-methyldodecyl acetate, the pheromone of Drosophila mulleru by a deprotonation/methylation sequence starting with 1 -dodecanol in 59 % overall yield and very high enantioselectivity (98% ee)43. 

C13H26O, Mr 198.35, does not occur in nature. It is a clear, colorless to pale yellowish liquid, 0.910-0.915, Uq 1.472-1.475, with a woody, cedarlike odor. It can be prepared from dodecanol sodium by reaction with methyl halogenide. It is used as a stable wood fragrance in technical perfumery. 

Temperature-dependent data have been selected for 25°C as far as available in these sources, unless the solvent is not liquid at this temperature. Such solvents, from among the List, are /-butanol (No. 310), c-hexanol (No. 360), -dodecanol (No. 390), 1,4-butanediol (No. 540), phenol (No. 590), 2-methylphenol (No. 600), 4-methyl- phenol (No. 620), 2-methoxyphenol (No. 630), 3-chlorophenol (No. 650), phenyl-acetone (No. 1060), / -methylacetophenone (No. 1070), benzophenone (No. 1090), ethylene carbonate (No. 1350), diethanolamine (No. 1940), 2-cyanopyridine (No. 2040), N-methylacetamide (No. 2240), di- -butylsulfoxide (No. 2410), sulfolane (No. 2420) hexamethyl thiophosphoramide (No. 2520), hydrogen fluoride (No. 2540), ammonia (No. 2560), and sulfur dioxide (No. 2580). Several of these have melting points sufficiently close to 25°C, so that they are readily used in the slightly supercooled state, and values for this... 

The simple compound 79 is an aggregation pheromone of the fruit fly Drosophila mulleri. Hoppe proposed to synthesise it by asymmetric deprotonation and retentive methylation of a carbamate derivative of n-dodecanol.8 Given that the carbamate group (required for directed oc-lithiation) must, at the end of the synthesis, be removed from the molecule, the best choice is the tetramethyloxazolidine-derived 81, readily formed by acylation with the carbamoyl chloride 80. Lithiation of 81 with excess s-BuLi-(-)-sparteine gives, by asymmetric deprotonation, a configurationally stable complex of organolithium 82 with (-)-sparteine. 

Lesser tea tortrix. A minor component of the sex pheromone blend of this moth is 10-methyl-l-dodecanol acetate, V, (Figure 10) (48). Mori has synthesized the enantiomers both compounds were constructed from (R)-(+)-citronellol (49). The racemic target compound was synthesized by alkylating 10-undecenoic acid (as its dianion) with ethyl iodide (50). Reduction of the carboxyl to a methyl group was accomplished by standard procedures. Hydroboration of the olefinic link with disiamylborane and oxidative workup yielded the primary alcohol which was then acetylated to give the racemic pheromone structure. The overall yield from undecenoic acid was 40-45% without any extensive effort to optimize. 

Conversely, the decrease in the rate constant for the hydroxide ion catalyzed reaction of l,l,l-trichloro-2-methyl-2-propanol in the presence of polyoxyethylene(23) dodecanol and polyoxyethylene sorbitan mono-decanoate has been rationalized by assuming that the nucleophilic reaction occurs only in the bulk solution and that a substantial fraction of the substrate is solubilized by the surfactant. The latter assumption was verified by measurements of the solubility of l,l,l-trichloro-2-methyl-2-propanol, and hence the distribution coefficients, in the micellar systems (Anderson and Slade, 1966). 

DithiomethoxymethyIphenol, 306 Di-p-toluoyl-o-tartrate, 351 Di-p-tolylcarbodiimide, 351-352, 1148 1,1-Di-p-tolylethane, 11, 659 Di-p-tolylthiourea, 351 N,0-Ditosyl-3-aminopropanol, 918 v/c-Ditosylates, 1089 Divinylmercury, 352-353 Docosanedioic add, 438, 708 -Dodecadiene, 1009 Dodecahydrotriphenylene, 991 Dodecane-l,2-dioic acid, 477,788 methyl ester amide, 212 Dodecanol, 958 Dodecanyl tosylate, 958-959... 

All protic solvents undergo multiple relaxation processes due to the presence of hydrogen bonding. In the case of water and formamide (F), the data can be described in terms of two Debye relaxations. For the alcohols and A-methyl-formamide (NMF), three Debye relaxations are required for the description. In all of these solvents, the low-frequency process involves the cooperative motion of hydrogen-bonded clusters. In the case of water and the alcohols the high-frequency process involves the formation and breaking of hydrogen bonds. The intermediate process in the alcohols is ascribed to rotational diffusion of monomers. Studies of dielectric relaxation in these systems have been carried out for the -alkyl alcohols up to dodecanol [8]. Values of the relaxation parameters for water and the lower alcohols are summarized in table 4.5. 

Bowers and Thompson (1963), after having established that the completely saturated hexahydrofamesol (17) is also effective, investigated several saturated, nonbranched alcohols and their methyl ethers. Of these, dodecanol and dodecyl methyl ether (18) were active. Similar results were reported by Schneiderman et al. (1965), who found that molecular dimensions play a decisive role in the exertion of the action. 

In the essential oil of St. John s Wort approx. 30 individual components were found using GC [94]. The most abundant constituents were 2-methyl-octane, a-pinene and dodecanol. Further lipophilic nonvolatile compounds such as alkanes, long-chain fatty alcohols, fatty acids and some carotenoids were also reported [2]. 

The results obtained are summarized in Table I. Chromatograms of aliphatic hydrocarbons, aromatic hydrocarbons, and fatty acids produced when potassium carbonate, rubidium carbonate, or magnesium carbonate was used as a promoter are presented in Figures 2, 3, and 4, respectively. The fatty acids obtained when a potential fatty-acid precursor (dodec-anal, 1-dodecanol, or 1-pentadecene) is added to a reaction are shown in Figure 5. The mass spectogram of the methyl ester of a n-Cs fatty acid (potassium carbonate- C used as promoter) is presented in Figure 6. 

FIGURE 16.2 Oxyethylation of (a) dodecanol and (b) methyl dodecanoate in the presence of calcium-based catalyst at 185°C. 

Hreczuch, W. 1999. Comparison of the kinetics and composition of ethoxylated methyl dodecanoate and ethoxylated dodecanol with narrow and broad distribution of homologues. J. Surfact. Deterg. 2 287-292. 

Figure 4.12 GC of alcohols and methyl esters of acids. 1 Methanol, 2 Butanol, 3 Pentanol, 4 Hexanol, 5 Heptanol, 6 2-Ethylhexanol, 7 Octanol, 8 Dimethyl adipate, 9 Decanol, 10 Dimethyl-o-phthalate, 11 Dodecanol, 12 Tetradecanol, 13 Methyl palmitate,...

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