GB757998A - Manufacture of new tricyclic ketones - Google Patents

Abstract

The invention comprises (1) compounds of formula <FORM:0757998/IV(a)/1> wherein n is 1 or 2 and a free or functionally converted oxo (e.g. cyclic ketal) group is present in the a 1-position; (2) the selective reduction thereof to the corresponding a 1-hydroxyl derivatives; (3) the conversion of the a 1-hydroxyl group into a functional derivative thereof (e.g. an esterified hydroxyl group); and (4) the splitting off of a free or functionally converted a 1-hydroxyl group with the formation of a double bond between the a 1 and b 1 carbon atoms. Diketones of the above formula are prepared by treating a compound of formula <FORM:0757998/IV(a)/2> wherein the oxo groups are protected and X represent a carbamyl, preferably an N:N-dialkyl carbamyl, group, with a metal ethyl compound, and treating the product with a hydrolysing agent. The a 1-keto group may be subsequently selectively converted into a cyclic ketal group. The examples describe the preparation of D 8:14-1:7-dioxo-, D 8:14-1-hy droxy - 7 - oxo -, D 8:14 - 1 - benzoyloxy - 7 -oxo -, D 8:14 - 1 - oxo - 7 - ethylenedioxy - and D 1:8:14 - 7 - oxo - 8:11 - dimethyldodecahydrophenanthrenes, and D 8:9-3:8-dimethyl-7-oxo-3:4 - (31 - oxo - cyclopentano - 21:11) - octa hydronaphthalene. 1 - Carbethoxy - 6 - chlorohexane - 4 - one is prepared by treating glutaric acid monoethyl ester chloride with ethylene in presence of aluminium chloride. 1 - Methyl - 1 - (6 - carbethoxy - hex - 31 - oneyl) - cyclohexane - 2:6 - dione is prepared by reacting 1 - methyl - 6 - chlorohexane - 4 - one with 1 - methyl - cyclohexane - 2:6 - dione in presence of triethylamine. b - (1:6 - Dioxo - 9 - methyl - D 5:10 - octalyl-5) - propionic acid ethyl ester is prepared by ring closing 1-methyl-1-(61-carbethoxy-hex-3-one - yl) - cyclohexane - 2:6 - dione with benzoic acid and triethylamine in xylene. b - (1:6 - Dioxo - 9 - methyl - decalyl - 5) - propionic acid ethyl ester is prepared by hydrogenating b - (1:6 - dioxo - 9 - methyl - D 5:10-octyl - 5) - propionic acid ethyl ester in presence of palladium black. b - (1:6 - Dioxo - 9 - methyl - decalyl - 5) - propionic acid is prepared by hydrolysis of the corresponding ethyl ester, and may be converted to the methyl ester by treatment with diazo-methane. b - (1:6 - Di - ethylenedioxy - 9 - methyldecalyl - 5) - propionic acid methyl ester is prepared by boiling a benzene solution of b -(1:6-dioxo - 9 - methyl - decalyl - 5) - propionic acid methyl ester with ethylene glycol in presence of para-toluene sulphonic acid, hydrolysing the carboxylic ester group and re-esterifying with diazo-methane in ether. b - (1:6 - Di - ethylenedioxy - 9 - methyldecalyl - 5) - N - diethyl - and N - dimethyl - propionamide are prepared by treating b -1:6-diethylenedioxy - 9 - methyl - decalyl - 5) - propionic acid methyl ester with methyl magnesium iodide and diethylamine or dimethylamine respectively, and decomposing the product with saturated ammonium chloride solution. The former compound may also be prepared by heating a toluene solution of b -(1:6-dioxo - 9 - methyl - decalyl - 5) - propionic acid with diethylamine in a closed vessel and boiling a benzene solution of the resulting b -(1:6-di-oxo - 9 - methyl - decalyl - 5) - N - diethyl - propionamide with ethylene glycol in presence of para-toluene sulphonic acid.