Bromine → 21-Bromo-3alpha-hydroxy-5beta-pregnane-11,20-dione

HRID 1576788Notes

Reaction equation

HRID 1576788 reaction equation
[OH:1][C@@H:2]1[CH2:21][CH2:20][C@@:19]2([CH3:22])[C@H:4]([CH2:5][CH2:6][C@@H:7]3[C@@H:18]2[C:17](=[O:23])[CH2:16][C@@:15]2([CH3:24])[C@H:8]3[CH2:9][CH2:10][C@@H:11]2[C:12](=[O:14])[CH3:13])[CH2:3]1.[Br:25]Br>CO>[Br:25][CH2:13][C:12](=[O:14])[C@@H:11]1[C@:15]2([CH3:24])[C@H:8]([C@H:7]3[C@H:18]([C:17](=[O:23])[CH2:16]2)[C@:19]2([CH3:22])[C@@H:4]([CH2:3][C@H:2]([OH:1])[CH2:21][CH2:20]2)[CH2:5][CH2:6]3)[CH2:9][CH2:10]1

Participants

4

Reactant 2

HCID 24408BromineHCID 689303alpha-Hydroxy-5beta-pregnane-11,10-dione

Product 1

HCID 13171045821-Bromo-3alpha-hydroxy-5beta-pregnane-11,20-dione

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

A stirred solution of 3α-hydroxy-5β-pregnane-11,20-dione (10 g.) in dry methanol (700 ml.) was treated at 0° with a solution of bromine (1.9 ml.) in methanol (45 ml.) at such a rate that the yellow colour disappeared before further addition. The solution was then partitioned between water and chloroform. The organic layer was washed with water, dried (Na2SO4) and evaporated. Chromatography of the residue (with benzene/ethyl acetate, 2.5:1) gave title compound (7.2 g.) as a white foam; [α]D + 100°(c 1.1).

Workup

  1. additiondisappeared before further addition
  2. customThe solution was then partitioned between water and chloroform
  3. washThe organic layer was washed with water
  4. dry with materialdried (Na2SO4)
  5. customevaporated

Sources & evidence

ORD record
ord-6cb42139dc2e4b3ca49a513af8fd8ea1
Source dataset
uspto-grants-1976_09
Patent number
US03983111

Reaction notes

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