Sodium hydride → (S)-4-(2,5-dimethoxy-3,4,6-trimethylphenyl)-2-methyl-1,2-butanediol

HRID 1383088Notes

Reaction equation

HRID 1383088 reaction equation
[CH3:1][C@:2]([OH:7])([CH2:5]Cl)[CH2:3][OH:4].[H-].[Na+].[CH3:10][O:11][C:12]1[C:19]([CH3:20])=[C:18]([CH3:21])[C:17]([O:22][CH3:23])=[C:16]([CH3:24])[C:13]=1[CH2:14][Li].COC1C(C)=C(C)C(OC)=C(C)C=1C>O1CCCC1.O>[CH3:1][C@:2]([OH:7])([CH2:5][CH2:21][C:18]1[C:19]([CH3:20])=[C:12]([O:11][CH3:10])[C:13]([CH3:14])=[C:16]([CH3:24])[C:17]=1[O:22][CH3:23])[CH2:3][OH:4]

Participants

7

Reactant 4

HCID 24758Sodium hydrideHCID 6017651,4-Dimethoxy-2,3,5,6-tetramethylbenzeneHCID 11469077(2R)-2-methyl-3-chloropropane-1,2-diolHCID 178506853HCID 178506853, compound

Product 1

HCID 11129761(S)-4-(2,5-dimethoxy-3,4,6-trimethylphenyl)-2-methyl-1,2-butanediolYield 101.8%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

A solution of 9.78 g (80 mmol) of (2R)-2-methyl-3-chloropropane-1,2-diol in 100 ml of tetrahydrofuran was reacted with 4.3 g (180 mmol) of sodium hydride at room temperature by the portionwise addition while stirring for 1 hour. To the suspension obtained there was added dropwise, while stirring at room temperature, a solution of 88 mmol of 2,5-dimethoxy-3,4,6-trimethylbenzyl lithium (obtained by reacting 17.2 g (88 mmol) of 2,5-dimethoxy-1,3,4,6-tetramethylbenzene in 20 ml of n-pentane with 88 mmol of tert.butyl lithium at room temperature) and the mixture was subsequently stirred at room temperature for an additional 16 hours. The mixture was then treated with 50 ml of water while stirring, the volatile constituents were removed by distillation in a vacuum (~15 mbar) and the separated material was removed by filtration and washed with water. The filter residue was recrystallized from ether/hexane and there were obtained 23 g of (2S)-2-methyl-4-(2,5 -dimethoxy-3,4,6-trimethylphenyl)-1,2-butanediol in the form of white crystals with a melting point of 83°-85° C. and [α]D20 =+2.86° (c=1.5% in CHCl3).

Workup

  1. customTo the suspension obtained there
  2. additionwas added dropwise
  3. stirringwhile stirring at room temperature
  4. stirringwhile stirring
  5. customthe volatile constituents were removed by distillation in a vacuum (~15 mbar)
  6. customthe separated material was removed by filtration
  7. washwashed with water
  8. customThe filter residue was recrystallized from ether/hexane

Sources & evidence

ORD record
ord-60cb0ab754714d7597792bd146a8d22b
Source dataset
uspto-grants-1989_02
Patent number
US04808736

Reaction notes

Loading…