Patent GB-693850-A (GB)
Title: Pyrolysis of steroid adducts
IPC: C07J9/00
Filed: 1950-12-22
Abstract: The invention comprises alkyl 3-acyloxy-bisnor - 5 : 7 : 9(11) - cholatrienates, 3 - acyloxy - and 3 - acyloxy - 21 - acetoxy - 5 : 7 : 9(11) - pregnatrien - 20 - ones, 3 : 22 - diacyloxy - 5 : 7 : 9(11) : 20(22) - bisnor - cholatetraenes, and 3 : 20 - diacyloxy - 5 : 7 : 9(11) : 17(20) - pregnatetraenes; and the manufacture of these and other cyclopentanopolyhydrophenanthrene compounds containing double bonds in the 5- and 7-positions by elimination of the adduct radical from 5 : 8-adducts thereof with maleic acid or anhydride by heating said adducts in the presence of an organic amine to effect thermal decomposition thereof at a temperature substantially lower than that required to effect such decomposition by heat alone, e.g. between about 100 DEG  and about 225 DEG  C., preferably about 150-200 DEG C.  Suitable starting materials may be prepared as described in Specifications 680,733 and 693,770.  Preferred amines are secondary or tertiary aliphatic or cycloaliphatic amines containing up to 18 carbon atoms in the molecule, secondary or tertiary aminoalcohols, primary, secondary or tertiary aromatic amines having one aromatic nucleus linked to the nitrogen atom, secondary or tertiary aralkylamines, and heterocyclic amines containing up to 10 carbon atoms in the molecule.  Examples describe the decomposition of the maleic anhydride adducts of dehydroergosteryl acetate, ergosteryl acetate, methyl 3(b )-acetoxy-bisnor-5 : 7 : 9(11) - cholatrienate, 3(b ) - acetoxy - and 3 : 21 - diacetoxy - 5 : 7 : 9(11) - pregnatrien - 20 - one, 3(b ) : 22 - diacetoxy - 5 : 7 : 9(11) : 20(22) - bisnor - cholatetraene and 3(b ) : 20 - diacetoxy - 5 : 7 : 9(11) : 17(20) - pregnatetraene, and the maleic acid adducts of dehydroergosteryl heptoate, dehydroergosterol and 5 : 7 : 9(11)-pregnatrien - 3 : 20 - dione, the following amines being used: diethylaminoethanol, dimethylaminoethanol, dimethylaniline, diethylamine, N : N - dimethylbenzylamine, aniline, morpholine, N - ethylpyrrolidine, quinoline and piperidine.  Lists of additional starting materials and amines are given.  3 - Acyloxy - 5 : 7 : 9(11) - bisnor - cholatrien - 22-aldehydes are obtained if 3 : 22-diacyloxy-5 : 7 : 9(11) : 20(22) - bisnor - cholatetraenes prepared as above are heated for a short time in solution in dilute alcoholic hydrochloric acid.  Maleic anhydride adducts of esters of 3-acyloxy - bisnor - 5 : 7 : 9(11) - cholatrienic acids are obtainable by esterification of the corresponding acids obtained by ozonization of dihydroergosterol ester adducts with 1.25-2.5 moles. of ozone per mole. of adduct.  Maleic acid or anhydride adducts of 3-acyloxy-21 - acetoxy - 5 : 7 : 9(11) - pregnatrien - 20 - ones are obtainable by treating the corresponding 3 - acyloxy - or 3 - hydroxy - 5 : 7 : 9(11) - pregnatrien-20-one adducts with lead tetra-acetate. Maleic acid or anhydride adducts of 3 : 20-diacyloxy - 5 : 7 : 9(11) : 17(20) - pregnatetraenes are obtainable by heating the corresponding 3-hydroxy- or 3-acyloxy-5 : 7 : 9(11)-pregnatrien-20-one adducts with a large excess of an organic carboxylic acid anhydride in the presence of a small amount of an alkali metal salt of the corresponding acid, or of an acid catalyst such as p-toluenesulphonic or sulphuric acid.