Steroidal Sapogenins. XI. Experiments in the Hecogenin Series (Part 2)

Steroidal Sapogenins. XIV.1 Δ4, 6-22-Isospirostadien-3β-Ol and Δ2, 4, 6-Isospirostatriene

“…A similar, stereospecific reduction has recently been observed ( 14) with 4• 6-cholestadien-3-one. The synthetic 4• 6-dien-3/S-ol and derivatives (IVa-c) agreed fairly well in their properties with the by-products isolated earlier (7) in the dehydrobromination of VI, and the dextrorotatory shift of the synthetic dienol IVa as compared to the 5> '-isomer coincided with that reported in the literature for other series (3,8,14,15). As has already been demonstrated with 4• 6-cholestadien-3/3-ol (16), Oppenauer oxidation of the dienol IVa regenerated the dienone III.…”

“…originally by Eckhardt (17), who proposed the 8• 5• 7-triene (IX) formulation for it. 3 The correct 3• 5• 7-cholestatriene was recently prepared by Gould, et al, (18) who showed that such a compound was characterized by a strongly negative rotation ([a]D -122°), ultraviolet absorption maxima at 302.5, 315, and 330 µ, and by the uptake of only two moles of hydrogen upon catalytic hydrogenation (the 7,8-double bond not being reduced). Eckhardt's triene (17), on the other hand as was recently confirmed by Schmutz, Schaltegger, and Sanz (14), exhibits a much more positive rotation ([a]D -13.5°), and ultraviolet absorption maxima at 295, 305 µ, and an inflection at 320 µ, in excellent agreement with the maxima observed for our triene V. As pointed out by the Swiss workers (14), the physical data, the fact that the triene takes up three moles of hydrogen, and that it forms an adduct with maleic anhydride, all support a 2•4 *• 6-cholestatriene structure.…”

STEROIDAL SAPOGENINS. XVIII.1 EXPERIMENTS IN THE 5,6-DIHYDROKRYPTOGENIN SERIES

“…For further characterization, the free furostadiene Ha was prepared and the previously unreported rotations were determined of the various intermediates. The dextrorotatory shift, typical (1,4) for the conversion to a furostene derivative, was observed in this instance also and serves as further confirmation for structure II. Chromium trioxide oxidation of the furostadiene diacetate lib afforded an oil with an ultraviolet absorption spectrum at 246 m¿i, which ivas shown to have the constitution of A17(20)-cholestene- absorption maximum at 237 µ) which upon refluxing with hydrazine hydrate in ethylene glycol was transformed into the identical pyridazine V. Finally lithium aluminum hydride reduction of IV led to A17(20)-22-isoallospirosten-3l8-ol (Via) (no selective absorption in the ultraviolet), which formed a monoacetate…”

Synthesis of Δ9(11)- and Δ20(22)-Cholestenol

“…(1) Wisconsin Alumni Research Foundation Research Assistant, 1949-1950Syntex Fellow, 1950-1951Homer Adkins Fellow, 1951-1952 (2) C. B. Wooster, XL S. Patent 2,182,242 (Dec. 5, 1939); see also C. B. Wooster and K. L. Godfrey, This Journal, 69, 596 (1937). f3) (a) A recent reference: A. J. Birch, J.…”