Water → 3alpha-Hydroxy-21-bromo-16alpha-methyl-5alpha-pregnane-11,20-dione

HRID 918053Notes

Reaction equation

HRID 918053 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][C@@H:10]([CH3:25])[C@@H:11]2[C:12](=[O:14])[CH3:13])[CH2:3]1.[Br:26]Br.O>CO>[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][C@@H:10]([CH3:25])[C@@H:11]2[C:12](=[O:14])[CH2:13][Br:26])[CH2:3]1

Participants

5

Reactant 3

HCID 962WaterHCID 24408BromineHCID 705839113alpha-Hydroxy-16alpha-methyl-5alpha-pregnane-11,20-dione

Product 1

HCID 1317103893alpha-Hydroxy-21-bromo-16alpha-methyl-5alpha-pregnane-11,20-dione

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Procedure

3α-Hydroxy-16α-methyl-5α-pregnane-11,20-dione (5 g.) was dissolved in dry methanol (350 ml.) and treated at 0° with a solution of bromine (1 ml.) in dry methanol (24 ml.) at such a rate that the yellow colour disappeared before further addition. After completion of the addition the mixture was poured into water. The precipitated product was dried and dissolved in chloroform (20 ml.) and put onto a column of silica gel MFC (700 g.). Elution with benzene:ethyl acetate (21/2:1) gave the title compound (3.6 g.) as a foam, [α]D + 112.4°.

Workup

  1. additiondisappeared before further addition
  2. additionAfter completion of the addition the mixture
  3. customThe precipitated product was dried
  4. dissolutiondissolved in chloroform (20 ml.)
  5. washElution with benzene:ethyl acetate (21/2:1)

Sources & evidence

ORD record
ord-6866224abbd44be1aa5afbda40caaf8e
Source dataset
uspto-grants-1976_07
Patent number
US03969345

Reaction notes

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