Reaktion #87465

Reaktionsgleichung

1-bromomethyl-4-methoxy-benzene

((3S,4S,5R)-6-allyloxy-3,4,5-tris-benzyloxy-2-hydroxymethyl-tetrahydro-pyran-2-yl)-methanol

Sodium hydride

→

product

Ausbeute 52.0%

(3S,4S,5R)-6-allyloxy-3,4,5-tris-benzyloxy-2,2-bis-(4-methoxy-benzyloxymethyl)-tetrahydro-pyran

Ausbeute 52.0%

Lösungsmittel

N,N-dimethylformamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction was then heated to 60° C. overnight
2. 2
   TemperaturThe mixture was cooled down to room temperature
3. 3
   Sonstigethe reaction was quenched with water
4. 4
   Extraktionextracted with ethyl acetate (2 times)
5. 5
   WaschenThe combined organic layers were washed with water, brine
6. 6
   Trocknendried over sodium sulfate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under reduced pressure
9. 9
   SonstigeThe reaction was then chromatographed over silica gel (
10. 10
    Wascheneluting with a gradient of 0 to 80% ethyl acetate in heptane)

Vorschrift

The starting diol [((3S,4S,5R)-6-allyloxy-3,4,5-tris-benzyloxy-2-hydroxymethyl-tetrahydro-pyran-2-yl)-methanol (I-1b: 10 g, 19.208 mmol) was dissolved in N,N-dimethylformamide (70 mL) and cooled to 0° C. Sodium hydride (60% dispersion in mineral oil, 1.69 g, 42.3 mmol) was added and the reaction was allowed to stir at 0° C. for 1 hour before the addition of 1-bromomethyl-4-methoxy-benzene (5.96 mL, 40.3 mmol). The reaction was then heated to 60° C. overnight. The mixture was cooled down to room temperature and the reaction was quenched with water and extracted with ethyl acetate (2 times). The combined organic layers were washed with water, brine, dried over sodium sulfate, filtered and concentrated under reduced pressure. The reaction was then chromatographed over silica gel (eluting with a gradient of 0 to 80% ethyl acetate in heptane) yielding 7.55 g (52% yield) of product (I-1c). MS 778.8 (M+NH4+; positive mode).

Quelle