4-Toluenesulfonyl chloride → (R)-(-)-2,2-Dimethyl-1,3-dioxolan-4-ylmethyl p-Toluenesulfonate

HRID 2206942Notes

Reaction equation

HRID 2206942 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.[CH3:12][C:13]1([CH3:20])[O:17][C@@H:16]([CH2:18][OH:19])[CH2:15][O:14]1>CN(C1C=CN=CC=1)C.N1C=CC=CC=1>[C:1]1([CH3:11])[CH:6]=[CH:5][C:4]([S:7]([O:19][CH2:18][C@H:16]2[CH2:15][O:14][C:13]([CH3:20])([CH3:12])[O:17]2)(=[O:9])=[O:8])=[CH:3][CH:2]=1

Participants

5

Reactant 2

HCID 73974-Toluenesulfonyl chlorideHCID 736057(+)-Solketal

Product 1

HCID 6993835(R)-(-)-2,2-Dimethyl-1,3-dioxolan-4-ylmethyl p-ToluenesulfonateYield 90.9%

Reagents, catalysts & solvents 2

HCID 142844-(Dimethylamino)pyridineCatalystHCID 1049PyridineSolvent

Procedure

p-Toluenesulfonyl chloride (6.5 g, 34.1 mmol) was added portionwise over a period of 10 min to a solution of (S)-(+)-1,2-isopropylideneglycerol (3.0 g, 22.7 mmol) and DMAP (30 mg, 0.25 mmol) in anhydrous pyridine (30 mL) in a water bath. The resulting solution was stirred overnight. The pyridine was removed under reduced pressure, and the residue was diluted with ethyl acetate (50 mL), washed subsequently with water (2×40 mL), cold aqueous 1 M HCl (40 mL), saturated NaHCO3 (40 mL) and water (40 mL). The organic layer was dried over Mg2SO4, filtered and concentrated to give a light yellow oil. The crude product was purified by column chromatography (eluent: 10% ethyl acetate in hexane to 30% ethyl acetate in hexane) to afford (R)-2,2-Dimethyl-1,3-dioxolane-4-methanol p-toluenesulfonate i (5.91 g, 90.9% yield) as a colorless viscous oil.

Workup

  1. customThe pyridine was removed under reduced pressure
  2. additionthe residue was diluted with ethyl acetate (50 mL)
  3. washwashed subsequently with water (2×40 mL), cold aqueous 1 M HCl (40 mL), saturated NaHCO3 (40 mL) and water (40 mL)
  4. dry with materialThe organic layer was dried over Mg2SO4
  5. filtrationfiltered
  6. concentrationconcentrated
  7. customto give a light yellow oil
  8. customThe crude product was purified by column chromatography (eluent: 10% ethyl acetate in hexane to 30% ethyl acetate in hexane)

Sources & evidence

ORD record
ord-bfdbafd38c6a4567b81ece7e689e87f8
Source dataset
uspto-grants-2016_06
Patent number
US09375496B2

Reaction notes

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