Acetic anhydride reaction with ethylene glycol

The reduction of the lactone grouping of compound (119) required the preliminary protection of the two keto groups. Reaction with ethylene glycol formed the diketal, the controlled reduction of which with lithium aluminum hydride enabled the cyclohemiacetal (118) to be obtained. In itself, the reduction takes place with a high yield and the main difficulty is the deketalization of the extremely unstable compound (118). Consequently, the products of lithium aluminum hydride reduction were immediately acetylated with acetic anhydride to a mixture of the 21-mono-and 18,21-diacetates. Hydrolysis of this mixture with 90% acetic acid at 100 C led to the 21-acetate of dl -aldosterone (123). Deacetylation of the latter with potassium carbonate gave not only dl -aldosterone (124) with a yield of 50%, but also its 17o -epimer. Natural -aldosterone was obtained by the same route from the tZ-enantiomer of (119). By Wettstein s first method (Scheme 66), cZZ-aldosterone (124) was formed from Sarett s ketone (67) in 22 stages with an over-all yield of 1.7%. 

A powerful oxidizer. Explosive reaction with acetaldehyde, acetic acid + heat, acetic anhydride + heat, benzaldehyde, benzene, benzylthylaniUne, butyraldehyde, 1,3-dimethylhexahydropyrimidone, diethyl ether, ethylacetate, isopropylacetate, methyl dioxane, pelargonic acid, pentyl acetate, phosphoms + heat, propionaldehyde, and other organic materials or solvents. Forms a friction- and heat-sensitive explosive mixture with potassium hexacyanoferrate. Ignites on contact with alcohols, acetic anhydride + tetrahydronaphthalene, acetone, butanol, chromium(II) sulfide, cyclohexanol, dimethyl formamide, ethanol, ethylene glycol, methanol, 2-propanol, pyridine. Violent reaction with acetic anhydride + 3-methylphenol (above 75°C), acetylene, bromine pentafluoride, glycerol, hexamethylphosphoramide, peroxyformic acid, selenium, sodium amide. Incandescent reaction with alkali metals (e.g., sodium, potassium), ammonia, arsenic, butyric acid (above 100°C), chlorine trifluoride, hydrogen sulfide + heat, sodium + heat, and sulfur. Incompatible with N,N-dimethylformamide. 

AP (504-29-0) Reacts with water, forming a strong base. Violent reaction with strong oxidizers, strong acids, isopropyl percarbonate, nitrosyl perchlorate. Aqueous solutions incompatible with organic anhydrides, acrylates, alcohols, aldehydes, alkylene oxides, substituted allyls, cresols, caprolactam solution, epichlorohydrin, ethylene dichloride, glycols, isocyanates, ketones, maleic anhydride, nitrates, nitromethane, phenols, vinyl acetate. APARASIN (58-89-9) see lindane. APAVINPHOS (7786-34-7) see MEVINPHOS . 

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