Reaction #6352

Reaction equation

imidazole

t-butyldiphenylsilyl chloride

(R)-3-benzyloxypropane-1,2-diol

acetic acid

→

title compound

Yield 90.0%

(S)-1-Benzyloxy-3-(t-butyldiphenylsilyloxy)propan-2-ol

Yield 90.0%

Solvents

THF

Conditions

Workup

1. 1
   Otherby acid hydrolysis
2. 2
   OtherA white precipitate formed immediately
3. 3
   workup.WAITAfter 2 hours
4. 4
   Filtrationthe reaction mixture was filtered
5. 5
   Otherthe filtrate evaporated
6. 6
   OtherThe residue was partitioned between ethyl acetate and water
7. 7
   Otherthe organic layer separated
8. 8
   Washwashed with saturated brine
9. 9
   Dryingdried (MgSO4)
10. 10
    Filtrationfiltered
11. 11
    Otherevaporated
12. 12
    Otherto give a colourless oil

Procedure

To a solution of (R)-3-benzyloxypropane-1,2-diol (prepared from (S)-4-benzylymethyl-2,2-dimethyl-1,3-dioxolane (commercially available from FLUKA) by acid hydrolysis using 80% aqueous acetic acid), (8.3 g, 47.2 mmol) in dry THF (70 ml) was added imidazole (6.42 g, 94.4 mmol). After 2 minutes, t-butyldiphenylsilyl chloride (12.28 ml, 47.2 mmol) was added. A white precipitate formed immediately. After 2 hours, the reaction mixture was filtered and the filtrate evaporated. The residue was partitioned between ethyl acetate and water, the organic layer separated, washed with saturated brine, dried (MgSO4), filtered and evaporated to give a colourless oil. Chromatography of the oil on silica gel (dichloromethane as eluant) afforded the title compound as a colourless oil (17.72 g, 90%).

Source