Conformation and properties of Δ5(10)-steroids

Infrared and Ultraviolet Studies on the Tautomeric Equilibria in Aqueous Medium between Monoanionic Species of Uracil, Thymine, 5-Fluorouracil, and Other 2,4-Diketopyrimidines

“…Consequently eAT-:€Ai.MeT-= fractional content of 1-HT-in the mixture of the two monoanions, ~0.4.13 Calculation of Relative Concentrations of Tautomeric Monoanions from Ultraviolet Spectra. The procedure adopted by Nakanishi, et al,1 and Wempen and Fox6 for calculation of the relative concentrations of the two tautomeric monoanions made use of a "wing correction," based on the assumed symmetry of the long wave length absorption bands of the type II (10) Strictly speaking one should refer to 1-DT" and 3-DT-, but this is avoided in order to maintain uniformity in nomenclature throughout the text. (11) The pK& values for 1-MeT and 3-MeT have not hitherto been recorded.…”

Steroids. CCLXXXIII.1 Stereochemically Controlled Simmons-Smith Methylenation of Homoallylic Alcohols of Low Reactivity. A New Synthesis of 10α-Testosterone

“…The recent findings that metal hydride reductions of steroid 5(10)-en-3-ones (readily available from estrone 3-ethers by Birch reduction) give predominantly 5 (10)-en-3a-ols (C)10•11 suggested a simple chemical synthesis of 10a-androst-4-en-3-ones according to the scheme C -* F. mons-Smith methylenation of the 5( 10)-double bond.12 Isomerization of 5/3,19-cyclosteroids to 10/3-methyl steroids had already been realized using alumina14 and acid15 catalysis. For the 5a,19-cyclo-10a-steroid E, ring cleavage to the desired -methyl derivative F leads to a less stable, fused-ring system.…”

Steroids. CCXL.1,2 The Reaction of Steroidal Alcohols with 2-Chloro-1,1,2-trifluorotriethylamine

“…3 44.2 121.3 (OAc), 334 (3-H), 223 (=C-CH2-O) " See ref. 10. For comparison with various data reported in the literature the following chemical shift values have been employed: ^benzene -ptms = 384 c.p.s.…”

“…Reaction of 33-Hydroxyandrost-5-en-17-one (lie) with the Amine I.-A mixture of 30-hydroxyandrost-5-en-17-one (2.9 g., 10 mmoles), the amine I (2.85 g., 15 mmoles), and dry methylene chloride (25 ml.) was heated under reflux for 15 min.…”

“…The first crystalline fractions eluted with hexane consisted of 3hydroxy-17/3-methylgona-l,3,5 (10),13-tetraene-3-methyl ether (XXVI, 3.79 g., 47.1%), m.p. 65-75°.…”