Preparation from Alcohols

CaHjNCO, PhNCO. A pungent lachrymatory almost colourless liquid m.p. — 33 "C, b.p. 162°C. Used as a dehydrating agent and for characterization of alcohols. Prepared from aniline and phosgene in the presence of hydrogen chloride. 

Fatty amines are nitrogen derivatives of fatty acids, olefins, or alcohols prepared from natural sources, fats and oils, or petrochemical raw materials. Commercially available fatty amines consist of either a mixture of carbon chains or a specific chain length from C The amines are classified as... 

Eatty alcohols, prepared from fatty acids or via petrochemical processes, aldol or hydroformylation reactions, or the Ziegler process, react with ammonia or a primary or secondary amine in the presence of a catalyst to form amines (10—12). 

Roughly 65% of the substituents are trifluoroethoxy, and 35% are telomer alcohols prepared from tetrafluoroethylene and methanol. About 0.5 mol % of an aHyhc substituent is used as a cross-link site. The substituent pattern is beUeved to be stricdy statistical. 

The neopentyl alcohol, prepared from the sulfonyl chloride (Pyr, 95% yield), is cleaved nucleophilically under rather severe conditions (Mc4N CP, DMF, 160°, 16 h, 100% yield). ... 

Styrolyl Acetate.—Styrolene alcohol, or phenyl-ethyl glycol, is an alcohol prepared from styrolene dibromide by the action of caustic potash. It can be esterified, and forms an acetic ester of the formula CgHj. CH(OH)CHg. OOC. CHg. It is an ester with a fine flower odour, which has been described as fragrant and dreamy . It is generally stated by those who have used it that it is indispensable in the preparation of fine flower bouquets with a jasmin odour. 

Scheme 6.151 Range of allylic alcohols prepared from 145-catalyzed MBH reactions of2-cyclohexene-l-one with various aldehydes.

These observations were applied by Dimitrov, Hesse and coworkers. On stndying ozonization of a series of allylic and homoallylic alcohols prepared from (+) camphor and (—) fenchone, they were able to isolate a certain number of ozonides and to obtain the O NMR spectrum of the diastereomeric mixture of one of them, i.e. derivative 15, whose structure and O NMR chemical shifts (5, ppm) are shown below. 

Ortho ester Claisen rearrangement.2 The [3,3]sigmatropic rearrangement of allyl vinyl alcohols prepared from this ester results in a regiospecific synthesis of diethyl allylmalonates. 

Several allylic and homoallylic alcohols prepared from (+)-camphor and (-)-fenchone were ozonolyzed in EtzO at -78 °C and then treated with Et3N or LiAlH4 furnishing chiral hydroxyl carbonyl compounds and diols (the latter with high diastereoselectivity). Several relatively stable 1,2,4-trioxolanes were isolated and characterized by H, 13C, and 170 NMR spectra and by ESI-MS <1999HCA1385>. All stereoisomers of products 159 and 160 were isolated and characterized. 

Both Siegel et al. (122) and Lawrence et al. (123) have described automated systems for the purification of small arrays of amines and amides. A 48-member array of P-amino alcohols prepared from epoxides and amines was purified using SPE by Shuker et al. (124). Blackburn et al. (125) have described the purification of a 60-member 3-aminoimidazo[l,2-fl]pyridine array obtained from a multiple-component condensation, and Bussolari et al. (126) purified a small array of phenylpropyl amines obtained from dihydrocoumarins and amines. A few applications where ion-exchange resins have been substituted with other solid phases have also recently appeared. For example, the purification of several carbohydrate arrays tagged as hydrophobic O-laurates using Ci8 silica producing up to 10-30 mg of >90% pure individuals was described by Nilsson et al. (127), and Curran et al. purified fluorous-... 

A crucial step in the synthesis of thiotetronic acids involves a fully stereoselective allylic xanthate to dithiocarbonate rearrangement45. Rearrangement of ethyl ( )-(4S)-2-methyl-4-[methylthio-(thiocarbonyl)thio]-2-pentenoate (7) gives ethyl (/f)-(2.S)-2-methyl-2-[methylthio(curbonyl)thio]-3-pentenoate (8) as a single diastereomer with an -configurated double bond and at least 98% ee. This value was determined by Mosher derivatization of the alcohol prepared from the dithiocarbonate in three steps. The remainder of the (5S)-thiotetronic acid synthesis is shown in the scheme. 

To a solution of aluminum isopropoxide (p. 7) in isopropyl alcohol, prepared from 47 g. (2.0 gram atoms) of aluminum, there are added 210 g. (3.0 moles) of crotonaldehyde (b.p. 102-103°) and 11. of isopropyl alcohol. The mixture is heated at a bath temperature of 110° for 8-9 hours, and some of the solvent plus the acetone formed in the reaction is distilled slowly through an 80-cm. Vigreux column. The temperature of the vapor is 60-70°. The remaining solvent is... 

The dibromo compound is dehalogenated by agitating under a hydrogen atmosphere a mixture of 80 g. (0.23 mole) of the dibromo compound, 700 ml. of N aqueous sodium hydroxide solution, and a catalyst consisting of 2% palladium on polyvinyl alcohol prepared from 0.5 g. of palladium chloride (p. 244). To the resulting mixture is added 120 g. of sodium chloride, and the precipitated catalyst is removed by filtration. The filtrate is acidified and extracted with chloroform. Removal of the chloroform by distillation gives 35 g. (80%) of ethyl orcinol-6-carboxylate, m.p. 132-133°. 

From the alkoxymagnesium halide derived from a tertiary alcohol (prepared from the alcohol with ethyl-magnesium bromide) with phthalic anhydride in ether or an ether-dioxan mixture. 

Table 2. Vinyl Alcohols prepared from Vinyl Magnesium Halides...

Sam KK. How absolute alcohol prepared from rectified spirit. Apr A 1, 2012. http //www.inclusive-science-engineering.com/how-absolute-alcohol-prepared-from-rectified-spirit/. [accessed 19.11.14]. 

The structure of ( —) 2P-acetoxy-1 la-hydroxyverrucosane (544) was established as follows (Scheme 65). Jones oxidation of (544) gave a five-membered ketone (551). Acid treatment of the latter resulted in homoallylic ring expansion to homo-allylic ketoalcohol (552) which was converted via the tosylhydrazone into (548) identical with the homoallylic alcohol prepared from (547) via (545) (Scheme 64). That the 11-hydroxyl group was a was inferred from the remarkable downfield shifts exhibited by the C-10 and the C-12 methyl groups of the five-membered ketone (551) and the small solvent shift exhibited by the C-10 methyl group (553) and its homoallylic ring expanded product. 

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