N-bromobutanimide → (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(1-hydroxy-2-oxoethyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetate

HRID 513897Notes

Reaction equation

HRID 513897 reaction equation
[C:1]([O:4][C@H:5]1[CH2:22][CH2:21][C@@:20]2([CH3:23])[C@@H:7]([CH2:8][CH2:9][C@:10]3([CH3:40])[C@@H:19]2[CH2:18][CH2:17][C@H:16]2[C@@:11]3([CH3:39])[CH2:12][CH2:13][C@@:14]3([CH:31]([CH:33]4SCCCS4)[OH:32])[CH2:26][C:25](=[O:27])[C:24]([CH:28]([CH3:30])[CH3:29])=[C:15]32)[C:6]1([CH3:42])[CH3:41])(=[O:3])[CH3:2].C1C(=O)N(Br)C(=[O:46])C1>C(#N)C.O>[C:1]([O:4][C@H:5]1[CH2:22][CH2:21][C@@:20]2([CH3:23])[C@@H:7]([CH2:8][CH2:9][C@:10]3([CH3:40])[C@@H:19]2[CH2:18][CH2:17][C@H:16]2[C@@:11]3([CH3:39])[CH2:12][CH2:13][C@@:14]3([CH:31]([OH:32])[CH:33]=[O:46])[CH2:26][C:25](=[O:27])[C:24]([CH:28]([CH3:30])[CH3:29])=[C:15]32)[C:6]1([CH3:42])[CH3:41])(=[O:3])[CH3:2]

Participants

5

Reactant 2

HCID 67184N-bromobutanimideHCID 86690393(3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-((1,3-dithian-2-yl)(hydroxy)methyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetate

Product 1

HCID 86690392(3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(1-hydroxy-2-oxoethyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetateYield 55.7%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6342AcetonitrileSolvent

Procedure

To a solution of 103 (1.2 g, 1.945 mmol) in acetonitrile (20 ml) and water (5.00 ml) stirred in air at rt was added NBS (1.385 g, 7.78 mmol) in one charge. The reaction mixture was stirred at rt for 0.5 h, then quenched with Na2SO3 (solid), concentrated and the residue was extracted with EtOAc. The organic phase was washed with water and saturated brine, dried over sodium sulphate and concentrated in vacuo to give (3aR,5aR,5bR,7aR,9S,11aR,11bR,13aS)-3a-(1-hydroxy-2-oxoethyl)-1-isopropyl-5a,5b,8,8,11a-pentamethyl-2-oxo-3,3a,4,5,5a,5b,6,7,7a,8,9,10,11,11a,11b,12,13,13a-octadecahydro-2H-cyclopenta[a]chrysen-9-yl acetate (104) (1.09 g, 1.083 mmol, 55.7% yield) as a light yellow solid which was used without further purification.

Workup

  1. additioncharge
  2. customquenched with Na2SO3 (solid)
  3. concentrationconcentrated
  4. extractionthe residue was extracted with EtOAc
  5. washThe organic phase was washed with water and saturated brine
  6. dry with materialdried over sodium sulphate
  7. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-d940aedf68b34503a24a6138c52a7638
Source dataset
uspto-grants-2015_08
Patent number
US09102685B2

Reaction notes

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