Conanine

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... 

N-Methylen-bis-nor-conaniii rZu einer Losung vonO,3 g(0,92 mMol)N-Demethyl-N-cyan-conanin in 15ml THF wird unter Stickstoff 0,15 g (4 mMol) Lithiumalanat gegeben. Nach 4Stdn. bei 20°gieBt man die Losung zu 50 g Kaliumhydroxid in 100 ml Eiswasser. Die Extraktion mit Ather liefert ein einheitliches Rohprodukt Aus-beute 0,28 g (100% d. Th.) F 170° (aus Athanol). 

Nor-conanin Zu einer klarcn Losung von 0,2 g (5,3 mMol) Lithiumalanat in 10 ml THF wird unter Stickstoff 0,3 g (0,92 mMol) N-Demethyl-N-cyan-conanin in 3 ml THF gegeben. Man erhitzt 1 Stde. unter RiickfluB, kiihlt ab, versetzt mit einer Losung von 25 g Kaliumhydroxid in 50 ml Wasser und extrahiert mit Ather. Nach Abdamp-fcn des Losungsmittels erhalt man ein einheitliches farbloses Harz Ausbeute 0,28 g (100°/u d.Th.). 

Batrachotoxin, conanine, irehdiamine A, solanine, samandarine and tomatilhdine... 

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). 

Details are now available of the reactions of peracids and of hydrogen peroxide with the imines (10) and (11). The reactions of the product oxaziridines and nitrones with the same two oxidants were also discussed. The reactions of sodium borohydride, benzoyl chloride, and toluene-p-sulphonic acid with the hydroxy-nitrones (12) and (13) have been reported.12 The c.d. spectra of 2-substituted pyrrolidines have been compared with that of conanine (14).13... 

Treatment of the conanine (372) with bromine-aqueous sodium carbonate yields192 (100%) the conenium salt (375) which is readily converted into (376) (80%). Compound (376) is also formed starting from (373). When C-20 is substituted by two methyl groups as in (374) the product is (377). The conanine (373) is photo-oxygenated,193 in the presence of methylene blue, to (376). The nitrone (378) is quantitatively deoxygenated by triphenyl phosphite with trimethyl phosphite the reaction is more complex.194... 

In conanine-type alkaloids (282) the most important cleavage reactions involve either the loss of the methyl group at C-20 or the production of a fragment of mass 71, (282)->[283]->[284],166... 

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... 

For pyrrolidine N-oxides, one might a priori anticipate iminium ion formation to occur by a syn elimination process, since the N—O and adjacent Co—bonds cannot become antiperiplanar to each other. However, the N-oxide (29a) of the steroid alkaloid conanine reacts with acetic and trifluoroacetic anhydride exclusively by the anti pathway to give the exocyclic enamine (30 Scheme 6). Release of steric strain between the C-16 methylene and the ring methyl substituent is undoubtedly a major driving force in this reaction. More revealing is the reaction of N-oxide (29b), which would give the same enamine product if a syn pathway is favored. The observed formation of compounds (31) and (32) argues in favor of the anti elimination. 

These structures are characterized by intense ions of mass m/e 42-i-Ri-f R2 owing to fragmentation (/). The alternative flssion of the 20,21-linkage leading to M-15 ion generally occurs to a much smaller extent than in the conanine type (10,11). 

This alkaloid was isolated as a chromatographically homogeneous substance (mp 95°-100° [a]]) +27° in EtOH), from the, bark of H. antidysenterica (77). Although crystalline, it resisted all attempts at recrystallization from a variety of solvents. Its structure was indicated by mass spectrometry showing a fragmentation pattern characteristic of the A -methylpyrrolidine moiety of the conanine type (peaks at m/e 71, M-15) and of a primary amino group in position 3 (peak at m/e 56). 

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