Terpenoids. XVII. The Cactus Triterpenes ... - ACS Publications

The Cactus Triterpenes Thurberogenin and Stellatogenin' ... is presented on the basis of which it is suggested that the two cactus triterpenes thurber...
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added to ice-uater. The mixture was filtered to give 0.54 EtoH 241 rnp ( e 16,650) and 308 nip (e 20,100); g. of solid, m.p. 188-194.5'. Several crystallizations 1760, 1682, 1655 and 1610 cm.-'; [ a I P 5 D +102' ( C from acetone-petroleum ether gave 0.245 g. of the 160-01 0.956), [ M I D +335. 240 m p ( E 16,500); vmsx Anal. Calcd. for C2,H2803 (328.44): C, 76.79; H, 8.59. dione VIa, m.p. 202-203'; A,, 3420, 1712, 1658 and 1615 cm.-'; [ C P ] ~ ~+192" D (c 1.91), Found: C, 76.43; H, 8.81. [AMID +645. A4J7(20)-Pregnadiene-20-ol-3,16-dione 20-Acetate (V).A n d . Calcd. for C ~ , H B O(330.45): O~ C, 76.32; H, 9.15. A solution of 0.215 g. of the trione IV in 5 ml. of pyridine Found: C, 76.06; H, 9.02. and 3 ml. of acetic anhydride was allowed to stand 16 hours A4-Pregnene-16B-ol-3,20-dione 16-Acetate (VIb).--A at room temperature, poured into water, extracted with solution of 272 mg. of VIa in 4 ml. of pyridine and 2 ml. of ether and ethyl acetate, and the combined extracts were acetic anhydride was allowed to stand at room temperature treated with Norite and dried. Evaporation gave an oil. for 16 hours, poured into ice-water, and filtered to give 264 Six crystallizations from dilute acetone afforded 0.032 g. mg. of crude acetate ITb, m.p. 185-193". Several cry+ (13%) of the enol acetate IT,m.p. 203-203.5'; A,, 242 mp tallizations from acetone-uetroleum ether vielded 110 ( e 26,400); k;'TXKOH n a b s EtOH 241 rnp ( E 16,400) and 308 mg.