Lithium Bromide → 21-Bromo-20-methyl-1alpha,3beta-diacetoxypregna-5,7-diene

HRID 1587635Notes

Reaction equation

HRID 1587635 reaction equation
[CH3:1][CH:2]([C@@H:15]1[C@:32]2([CH3:33])[C@H:18]([C:19]3[C@H:29]([CH2:30][CH2:31]2)[C@:27]2([CH3:28])[C:22]([CH2:23][C@@H:24]([O:38][C:39](=[O:41])[CH3:40])[CH2:25][C@@H:26]2[O:34][C:35](=[O:37])[CH3:36])=[CH:21][CH:20]=3)[CH2:17][CH2:16]1)[CH2:3]OS(C1C=CC(C)=CC=1)(=O)=O.[Br-:42].[Li+]>CC(C)=O>[Br:42][CH2:3][CH:2]([CH3:1])[C@@H:15]1[C@:32]2([CH3:33])[C@H:18]([C:19]3[C@H:29]([CH2:30][CH2:31]2)[C@:27]2([CH3:28])[C:22]([CH2:23][C@@H:24]([O:38][C:39](=[O:41])[CH3:40])[CH2:25][C@@H:26]2[O:34][C:35](=[O:37])[CH3:36])=[CH:21][CH:20]=3)[CH2:17][CH2:16]1

Participants

4

Reactant 2

HCID 82050Lithium BromideHCID 8674694520-Methyl-1alpha,3beta-diacetoxy-21-p-toluenesulfonyloxypregna-5,7-diene

Product 1

HCID 6778834921-Bromo-20-methyl-1alpha,3beta-diacetoxypregna-5,7-diene

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of 51 mg of 20-methyl-1α,3β-diacetoxy-21-p-toluenesulfonyloxypregna-5,7-diene in 5 ml of acetone was added 100 mg of lithium bromide and the mixture was heated under reflux for 10 hours. The same isolation and purification procedure in Example 47 gave mg of 21-bromo-20-methyl-1α,3β-diacetoxypregna-5,7-diene, whose 1H NMR spectrum was identical with that obtained in Example 12.

Workup

  1. temperaturethe mixture was heated
  2. temperatureunder reflux for 10 hours
  3. customThe same isolation and purification procedure in Example 47

Sources & evidence

ORD record
ord-60e7270ee4c24ea4a9764571a02f72fa
Source dataset
uspto-grants-1993_06
Patent number
US05218109

Reaction notes

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