4-Toluenesulfonyl chloride → tert-butyl (3R)-3-methyl-4-(p-toluenesulphonyloxy)butyrate

HRID 2255Notes

Reaction equation

HRID 2255 reaction equation
[C:1]1([CH3:11])[CH:6]=[CH:5][C:4]([S:7](Cl)(=[O:9])=[O:8])=[CH:3][CH:2]=1.[OH:12][CH2:13][C@H:14]([CH3:23])[CH2:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17].C(N(CC)CC)C>ClCCl>[CH3:23][C@@H:14]([CH2:13][O:12][S:7]([C:4]1[CH:5]=[CH:6][C:1]([CH3:11])=[CH:2][CH:3]=1)(=[O:9])=[O:8])[CH2:15][C:16]([O:18][C:19]([CH3:22])([CH3:21])[CH3:20])=[O:17]

Participants

5

Reactant 3

HCID 73974-Toluenesulfonyl chlorideHCID 8471TriethylamineHCID 107259131,1-Dimethylethyl (3R)-4-hydroxy-3-methylbutanoate

Product 1

HCID 53813491tert-butyl (3R)-3-methyl-4-(p-toluenesulphonyloxy)butyrateYield 96.5%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

p-Toluenesulphonyl chloride (13.2 g) was added portionwise to a stirred mixture of tert-butyl (3R)-4-hydroxy-3-methylbutyrate (11 g), triethylamine (21 ml) and dichloromethane (120 ml) and the mixture was stirred at room temperature for 20 hours. The mixture was washed in turn with water and with a dilute aqueous sodium carbonate solution. The organic solution was filtered through phase separating paper and evaporated to give tert-butyl (3R)-3-methyl-4-(p-toluenesulphonyloxy)-butyrate as an oil (20 g): NMR(CDCl3) δ 7.6(2H,d), 7.33(2H,d), 3.92(2H,d), 2.45(3H,s), 2.18.2.47(2H,m), 2.0-2.15(1H,m), 1.42(9H,s), 0.95(3H,d).

Workup

  1. washThe mixture was washed in turn with water and with a dilute aqueous sodium carbonate solution
  2. filtrationThe organic solution was filtered through phase
  3. customseparating paper
  4. customevaporated

Sources & evidence

ORD record
ord-5075b6fc94804d6986741814d1b8f075
Source dataset
uspto-grants-1998_03
Patent number
US05728701

Reaction notes

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