5a-Conanin

Cholestane-3/3,5a-diol 3-acetate, 397 Cholestane-4a,5a-diol 4-tosylate, 398 Cholestane-5a,6a-diol 6-tosylate,394 5a-Cholestan-2-one, 57, 88, 427 10(5 4 H)ijAeo-Cholestan-5-one, 398 10(5 6)ij ieo-Cholestan-5-one, 392, 394 5a-Cholestan-3-one cyanohydrin, 359 5a-Cholestan-3-one cyanohydrin acetate, 360 5a-Cholestan-2a,3a-oxide, 42 5a-Cholestan-2/3,3/3-thiirane, 43 Cholest-5-ene-3, 19-diol, 268 Cholest-5-ene-3, 25-diol, 71 5(10->l/3H)flfc eo-cholest- 10(19)-ene-3/8,5a-diol 3-acetate, 397, 398 Cholest-4-ene-3,6-dione, 105 Cholest-4-en-3-one, 318 Chromium trioxide, 147, 150 5a-Conanine-3/3-ol-ll-one 3-acetate, 259 Cupric bromide, 210, 211 Cuprous chloride-catalyzed conjugate addition, 76, 80... 

Hydrocholest-4-ene, 108, 112 3 -Hydroxycholest-5-en-7-one, 378 3 -Hydroxy-5a-conanine-l 1-one, 259 17 -Hydroxy- la,5/3-cyclo-1 Oa-androstan-2-one acetate, 322... 

Nocardia restrictus is capable of oxidizing the conessine derivative 5a-conanin-3/i-ol (220) to both the A4-3-ketone 222 and the A1,4-3-ketone 221, the latter being the major product of the incubation (189). Preliminary screening experiments have demonstrated that Trichothecium rosevan transforms conessine (223), solanocapsine (224), jervine (225), and pseudojervine (226) (42). Transformation of the latter is claimed to produce 20-30% jervine by glycoside hydrolysis, along with an unidentified product that may be further biotransformation product of jervine. Jervine is also metabolized by Polystictus versicolor and Piricularia oryzae, but no products have been identified (42). 

Base-catalysed equilibration of 6a-nitrocholest-4-ene and the 6j8-isomer led to a 1 1 mixture in which the unusual stability of the 6j3-isomer was tentatively attributed to homoconjugation.The 20-azidopregnane (96) was converted into the imino-dimer (97) by reaction with Bp3-Et20 according to the Scheme 2. In a study of the reactions of halogens with 5a-conanine (98) it was observed... 

The partial synthesis of 5a-conanine was published by Jeger and Arigoni s group simultaneously with the partial synthesis of dihydro-conessine by Corey and Her tier. 

Starting material for the synthesis of 5a-conanine (II) was 20a-methylamino-5a-pregnan-3-one (CLXIII) which had been prepared in several steps from 3)3-acetoxy-5a-pregnan-20-one via the corresponding oxime. 

The ketone CLXIII was subjected to Wolff-Kishner reduction to give the base CLXIV which was converted to the chloramine CLXV on treatment with iV-chlorosuccinimide. The action of concentrated sulfuric acid in acetic acid solution generated 5a-conanine (21). 

As in the case of 5a-conanine, the Loeffler-Freytag reaction was applied in the synthesis of dihydroconessine by Corey and Hertler (138, 139). Starting from 3)3-acetoxy-20a-aminopregn-5-ene (48) they obtained 3j8-dimethylamino-20a-methylamino-5a-pregnane (L) by obvious reactions. The base was converted to chloramine CLXVI which upon irradiation with UV-light afforded the 18-chloro derivative CLXVII cyclizing readily to dihydroconessine (CXXVI). 

A soln. of 8 g. 5a-conanin-3 -ol in 5%-acetic acid treated with mercuric acetate, heated 2 hrs. at 100°, the resulting crude enamine (7.4 g.) dissolved in benzene, shaken with aq. 5%-NaOH soln. and treated with 4 portions of benzoyl chloride... 

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