CHOLESTANYL METHYL ETHER

A detailed procedure for the preparation of cholestanyl methyl ether from cholestanol has been published 11) and a survey of the usefulness of the reagent has also appeared 12). There appears to be no particular advantage to this procedure over the more convenient alternatives given above. 

S-ml. portions of water, and dried over anhydrous sodium sulfate. The solvent is removed on a steam bath in a stream of nitrogen and finally at reduced pressure. The crystalline residue of 0.207 g. (Note 7) is recrystallized in a 10-ml. conical flask from 1 ml. of acetone. When the flask has cooled to room temperature, 0.5 ml. of methanol is added, and the flask is chilled to +2° for 2 hours. The crystals are collected on a tared Hirsch funnel of 40-mm. diameter, washed on the funnel with two 0.5-ml. portions of ice-cold methanol, and dried for 2 hours at 40°/2 mm. The first crop of cholestanyl methyl ether thus obtained forms large colorless glistening plates, m.p. 85.5-86° (Note 8). An additional... 

The crude reaction product is slightly yellow and has a very faint ammoniacal odor. It may be dissolved in acetone on slow evaporation to dryness, the solution leaves large glistening transparent plates of good-quality cholestanyl methyl ether, m.p. 83-85°. 

Cholestanyl methyl ether has been prepared by catalytic hydrogenation of cholesteryl methyl ether 7 and of cholest-4-en-... 

Among the features of Volume 41 is the smallest-scale synthesis yet published in Organic Syntheses, namely, the preparation of 0.0005 mole of cholestanyl methyl ether by a generally useful methylation procedure that employs diazomethane and fluoboric acid (p. 9). Two preparations of isocyanides by dehydration of formamides are included. One of these, illustrated by cyclohexyl isocyanide (p. 13), is most suitable for aliphatic isocyanides while the other, illustrated by o-tolyl isocyanide (p. 101), is most suitable for aromatic isocyanides. 

ChOLESTANE, 30-METHOXY-, 41, 9 Cholestanol, etherification of, 41, 9 Cholestanyl methyl ether, 41, 9 Cinnamaldehyde, reaction with Wittig reagent, 40,86... 

Ethers, Esters, and Related Derivatives of Alcohols.—5a-Cholestanyl methyl ether has been cleaved inter alia) and converted into 5a-cholestanol by successive treatment with trimethylsilyl iodide and water.Pyridinium toluene-p-sulphonate has been reported as an efficient and mild catalyst for the conversion of alcohols into their tetrahydropyranyl ethers.Bile acids were efficiently performylated by treatment with 90% HCO2H-HCIO4. Selective base-catalysed... 

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