Patent GB-476749-A (GB)
Title: Improved manufacture of compounds of the pregnane series
IPC: C07J75/00
Filed: 1936-06-24
Abstract: Saturated and unsaturated compounds of the pregnane series are prepared by dehydrogenating saturated or unsaturated pregnanolones, pregnane diols or their derivatives with the aid of dehydrogenating catalysts and the application of hydrogen acceptors and/or reduced pressure.  Starting materials mentioned are pregnanol-(3)-one-(20), pregnanol-(20)-one-(3), pregnane-diols or monosubstituted pregnane diols.  Substitutents mentioned include halogen compounds, organic and inorganic esters, and ethers.  Catalysts mentioned are finely divided copper, silver, gold, iron, nickel, platinum, palladium and zinc, or mixtures containing such metals or alloys such as brass and zinc-copper couples.  Other catalysts are metal oxides such as copper oxide, and metal salts.  Hydrogen acceptors mentioned include ketones such as cyclohexanone, benzophenone or quinone, aldehydes, and unsaturated compounds such as cinnamic acid, fumaric acid, quinoline, naphthalene, phenols and polyenes.  The reaction may also be carried out in the presence of inert gases such as nitrogen, carbon dioxide or the noble gases.  In examples: (1) D <5> : <6>-pregnanol-3-one-(20) is heated to 200 DEG  C. with copper powder in a vacuum to yield D <4> : <5>-pregnendione-(3 : 20).  Instead of copper powder there may be used as catalyst palladium platinum or silver; (2) D <5> : <6>-pregnenol-3-one-(20) is heated with zinc-copper couple in the presence of cyclohexanone or quinoline, if desired in a stream of nitrogen to give D <4> : <5>-pregnene dione-(3 : 20). In a similar manner pregnanol-(3)-one-(20) or pregnanol-(20)-one-(3) may be dehydrogenated.ALSO:Saturated or unsaturated compounds of the pregnane series are prepared by dehydrogenating saturated or unsaturated pregnandones, pregnane diols or their derivatives with the aid of dehydrogenating catalysts and the application of hydrogen acceptors and/or reduced pressure. Starting materials mentioned are pregnanol-(3)-one-(20), pregnanol-(20)-one-(3) pregnane diols or monosubstituted pregnane diols.  Substituents mentioned include halogen compounds, organic and inorganic esters and ethers.  Catalysts mentioned are finely divided copper, silver, gold, iron, nickel, platinum, palladium, and zinc, or mixtures containing such metals, or alloys such as brass and zinc-copper couples.  Other catalysts are metal oxides such as copper oxide, and metal salts.  Hydrogen acceptors mentioned include ketones such as cyclohexanone, benzophenone, or quinone, aldehydes, and unsaturated compounds such as cinnamic acid fumaric acid, quinoline, naphthalene, phenols and polyenes.  The reaction may also be carried out in the presence of inert gases such as nitrogen, carbon dioxide and the noble gases.  In examples: (1) D <5 : 6>-pregnenol-(3)-one-(20) is heated to 200 DEG  C. with copper powder in a vacuum, to yield D <4 : 5>-pregnendione-(3 : 20).  Instead of copper powder there may be used as catalyst palladium, platinum or silver; (2) D <5 :  > 6-pregnenol-(3)-one-(20) is heated with zinc-copper couple in the presence of cyclohexanone or quinoline, if desired in a stream of nitrogen to give the same D <4 : 5>-pregnene dione-(3 : 20) as obtained in example (1).  In a similar manner pregnanol-(3)-one-(20) or pregnanol-(20)-one (3) may be dehydrogenated.