The Hydration of Unsaturated Steroids by the Brown Hydroboration Reaction. II.¹ Steroidal Conjugated Dienes

Abstract

The diol LV (0.5 g. in 40 cc. of tetrahydrofuran) was hydrated by method a, and the product was chromatographed on 15 g. of alumina. Elution with chloroform-methanol (4:1)

Photochemistry and Photophysics of Cholesta-5,7,9(11)-trien-3β-ol in Ethanol

“…The UV spectra of the conjugated s - trans -diene, HOD 1 , λ max = 242 nm, and of the s - trans -diene ether products, HOE 1 and HOE 2 , λ max = 243 nm, account for the λ max of the product mixture in Figure 1 . Windaus et al reported λ max = 245 nm [ 20 ] for 3 β -Δ 7,9 -cholestadienol and a more recent measurement gave λ max = 243 nm [ 21 , 22 ]. The UV spectra of HOD 1 and HOE 1 are very similar ( Figure 2 ), reflecting the shared presence of the s - trans -diene chromophore.…”

Synthesis of cholest-5-ene-3.beta.,11.alpha.15.beta.-triol-7-one. A model for the steroid nucleus of oogoniol, a sex hormone of the water mold Achlya

“…With these two schemes in mind, the starting material chosen for the synthesis of 4 was cholesta-7,14-dien-3/3-ol benzoate (7a),10 obtained from the acid-catalyzed doublebond isomerization of 7-dehydrocholesterol benzoate.11 Sondheimer and co-workers have reported that the hydroboration of steroidal 7,9(ll)-dienes produces A7-l la-alcohols in good yield. 12 The selectivity and stereospecificity of this reaction was accounted for by their observation that A7 double bonds are unreactive and A9(U) steroids yield the 1 la-hydroxy compounds in the hydroboration reaction. These results suggested that the hydroboration of a 7,14-diene should produce the A7-15a-alcohol.…”

“…14 Hz), 4.20 (m, 1H, 15/3-H, wy2 ca. 14 Hz), 5.44 (m, 1H, 7-H); mass spectrum m/e 402 (47%, M+), 387 (39, M -CH3), 384 (100, M -H20), 369 (36, M -H20 + CH3), 351 (15, -2H20 + CH3), 317 (11), 290 (20, M -C7H12O (RDA from 7 double bond)29), 289 (10, Mside chain), 271 (84, -H20 + side chain), 257 (22, M -H20 + C9H19), 253 (13, -2H20 + side chain), 247 (16), 235 (12), 112 (48, C7Hi20(RDA)).…”

“…Acetylation of the triolenone (11a) (50 mg) with excess acetic anhydride (0.5 mL) in pyridine (1 mL) at room temperature overnight yielded 62 mg of pale yellow crystals of the triacetate derivative lib: mp 160-162 °C (MeOH); [«]20D +140°(c 1.08); IR 1725,1672 cm"1 (C=0); NMR 0.62 (s 3 H, 18-CH3; caled16•32 0.72), 1.14 (s, 3 H, 19-CH3; caled15•32 1.29), 2.05, 2.08, 2.10 (3 X s, 9 H, -OAc), 2.80 (d, 1 , 14a-H, J = 10 Hz), 4.70 (m, 1 , 3a-H, toy2 ca. 18 Hz), 5.72 (2 X m, 2 H, 11/3-H and 15/3-H); UV Xmax 249 (log e = 4.00); CD34 [0]218 -21 200, [fl]248 +47 600, [0]286 -452, [0]362 + 27 70; mass spectrum m/e 498 (7%, M -AcOH), 457.3311 (16, M -C4H503; caled for C29H4604: 457.3318), 456.3236 (26, M -C4H604; caled for C29H4404: 456.3239), 455.3165 (28, M -AcOH + C2H30; caled for C29H4304: 455.3161), 440.3287 (46, M -C4H604; caled for C29H4403: 440.3290), 438 (21, M -2AcOH), 423 (12, M -2AcOH + CH3), 353 (11), 351.1967 (25; caled for C23H2703: 351.1960), 338 (12), 327 (41, M -C4H604 + side chain), 325 (32, M -2AcOH + side chain), 311.1651 (63, M -2AcOH + C9H19; caled for C20H2sO3: 311.1647), 298.1574 (100, M -2AcOH + Ci0H20; caled for Ci9H2203: 298.1569), 287 (12), 284 (13).…”

Directing Effects in the Hydroboration of Steroidal Alkenes

“…These results were interpreted in terms of boracycle formation. In the steroid series hydroboration of cholesta-3, 5-and 4,6-diene and oxidation of the boranes was reported 38 to give entirely a 1,3-diol, cholestan-4α,6α-diol (26→27).…”