HCID 10030981, compound → HCID 10460748, compound

HRID 357273Notes

Reaction equation

HRID 357273 reaction equation
[Si:1]([O:8][CH2:9][CH2:10][CH2:11][C@H:12]([C@@H:14]1[C@:31]2([CH3:32])[C@H:17]([C@H:18]3[C@H:28]([CH2:29][CH2:30]2)[C@:26]2([CH3:27])[C:21]([CH2:22][C@@H:23]([O:33][CH:34]4[CH2:39][CH2:38][CH2:37][CH2:36][O:35]4)[CH2:24][CH2:25]2)=[CH:20][C:19]3=[O:40])[CH2:16][CH2:15]1)[CH3:13])([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]>CCOC(C)=O.[Pt](=O)=O>[Si:1]([O:8][CH2:9][CH2:10][CH2:11][C@H:12]([C@@H:14]1[C@:31]2([CH3:32])[C@H:17]([C@H:18]3[C@H:28]([CH2:29][CH2:30]2)[C@:26]2([CH3:27])[C@H:21]([CH2:22][C@@H:23]([O:33][CH:34]4[CH2:39][CH2:38][CH2:37][CH2:36][O:35]4)[CH2:24][CH2:25]2)[CH2:20][C:19]3=[O:40])[CH2:16][CH2:15]1)[CH3:13])([C:4]([CH3:5])([CH3:6])[CH3:7])([CH3:3])[CH3:2]

Participants

4

Reactant 1

HCID 10030981HCID 10030981, compound

Product 1

HCID 10460748HCID 10460748, compoundYield 71%

Reagents, catalysts & solvents 2

HCID 345198Adams' catalystCatalystHCID 8857Ethyl AcetateSolvent

Procedure

Compound 2004 (1.0 g, 1.75 mmol) was dissolved in EtOAc (75 ml) and platinum(IV) oxide (0.012 g, 0.049 mmol) was added. The mixture was placed on a hydrogenation apparatus (atmospheric). The set-up was evacuated to remove the dissolved oxygen and then hydrogen was introduced. The evacuation and introduction of hydrogen process was repeated 2 times. The reaction was stirred under hydrogen at atmospheric pressure for 2.5 hours. The reaction mixture was filtered through Celite and concentrated in vacuo. The crude product was purified by flash chromatography (SiO2, hexanes:EtOAc gradient starting with 20:1) giving compound 2005 as a white solid (0.70 g, 71%). 24-t-Butyldimethylsilyloxy-3β-tetrahydropyranyloxy-5α-cholan-7β-ol was obtained as a by-product (21%). (Note: This by-product could be converted to the desired ketone 2005 with Collin's reagent in 64% yield.) Compound 2005: 1H NMR (500 MHz, CDCl3): δ: 4.73-4.66 (m, 1 H, THP methine H), 3.95-3.85 (m, 1 H, THP CH2O), 3.66-3.52 (m, 3 H, THP CH2O & C-24 H), 3.50-3.45 (M, 1 H, C-3 H), 1.08 (s, 3 H, C-19 H), 0.91 (d, J=6.6 Hz, C-21 H), 0.89 (s, 9 H, t-Bu), 0.64 (s, 3 H, C-18 H), 0.04 (s, 6 H, TBDMS CH3); IR (CHCl3) 2900, 1685 cm-1 ; MS (CI/isobutane) m/z 575 (M+1, 85%), 491 (M+1-THP, 100%); m.p. 166°-170° C.; Anal. calcd. for C35H62O4Si: C=73.12, H=10.87; Found: C=72.88, H=10.78.

Workup

  1. customThe set-up was evacuated
  2. customto remove the dissolved oxygen
  3. additionhydrogen was introduced
  4. filtrationThe reaction mixture was filtered through Celite
  5. concentrationconcentrated in vacuo
  6. customThe crude product was purified by flash chromatography (SiO2, hexanes:EtOAc gradient starting with 20:1)

Sources & evidence

ORD record
ord-fb3aab39081046a1bce675dbd46bae11
Source dataset
uspto-grants-1998_11
Patent number
US05840740

Reaction notes

Loading…