Über Steroide, X. Eine neue Darstellungsweise der Desoxycholsäure

Abstract

Die Darstellung der Desoxycholsaure aus in 7-Stellung acetyliertem Cholsaure-methylester wird beschrieben.

Synthesis of 5.beta.-chol-7-en-6-one analogs of ecdysone from cholic acid

“…The starting material, 3a,12a-dinitroxy-7a-hydroxy-5/3cholan-24-oic acid (1), was synthesized by a modified procedure (Scheme I) (5,10). The methyl ester 2 was dehydrated with POCI3 in pyridine under anhydrous conditions to yield exclusively 3; if the methyl ester 2 is not scrupulously dried some 7/3-chloro substituted product is also obtained.…”

“…This yielded 108 g of methyl 3a,12a-dihydroxy-7a-acetoxy-5/3-cholan-24-oate: ymax 3400 ). This diol (108 g) was dissolved in CHCI3 (600 mL) and fuming nitric acid reagent (prepared by combining 450 mL of fuming HN03, specific gravity 1.6, with 1070 mLof Ac2Oat-5 °C) (10) was slowly added while maintaining the temperature at -5 °C. After stirring for 1 h, the reaction mixture was poured into ice water and the separated chloroform layer was washed with NaHC03 solution.…”

Synthesis of quassinoids. 5. Conversion of D-ring seco derivatives of cholic acid to .delta.-lactones

“…Fuming HNO3 (1 mL) was added to Ac20 (3 mL) at -5 °C. 7 To this mixture, a solution of 2b (0.3 g) in CHCI3 (5 mL) was added dropwise and stirred for 0.5 h. Workup and column chromatography afforded 2c (0.22 g): 7max 1740 and 1250 (OAc), 1715, and 1630,1280,860, and 760 cm-1 (NO3); 1H NMR 5.37 (peak, 1 , 12/3-H), 4.85 (peak, 1 H, 7/3-H), 4.5 (hump, 1 , 3/3-H), 2.9 (t, 1H, C-17), 2.08 (s, 3 H, C-20), 2.06 and 2.02 (s, 3 H each, 3a,7a-OAc's), 0.97 (s, 3 H, C-19), and 0.83 (s, 3 H, C-18); m/e (%) 479 (2, M+), 436 (7, M -CH3CO), 419 (7, M -HOAc), 373 (3, M -CH3CO -HN03), 359 (63, M -2HOAc), 313 (33, 359 -N02), 295 (57,359 -HNOg), 281 (39), 271 (46,313 -CH2CO), and 253 (87). 3a-Hydroxy-7a,12a-diacetoxy-5/S-pregnan-20-one (2e).…”

“…Spectroscopic comparison (IR, NMR, MS) of aequaline with compound 3 showed tliat aequaline did not have the structure assigned to it. Two diphenolic 2,3,9,10-substituted isomers of compounds 2 and 3 have been isolated from natural sources and are named discretamine (6)11•12 and stepholidine (7). 13•14 Both compounds have recently been synthesized.15 A comparison of aequaline with discretamine and stepholidine (IR, NMR, mass spectrometry, TLC) showed clearly that aequaline is identical with discretamine.…”