Benzyl Bromide → 1,4-Benzodioxan

To a stirred suspension of sodium hydride (60% in mineral oil, 2.2 g, 54.64 mmol) in DMF (40 ml), was added a solution of (2S,3R,4R,5S,6R)-2-[3-(2,3-dihydro-benzo[1,4]dioxin-6-ylmethyl)-4-ethyl-phenyl]-6-trityloxymethyl-tetrahydro-pyran-3,4,5-triol (8.0 g, 12.14 mmol) in DMF (10 ml) at 0° C. After stirring for 4 h at room temperature, reaction mixture was cooled to 0° C. and added TBAI (0.45 g, 1.21 mmol) followed by benzyl bromide (5.1 ml, 42.50 mmol). Then it was allowed to attain room temperature and stirred for overnight. Reaction mixture was poured into ice cold water and extracted with ethyl acetate (2×80 ml). Combined organic layers were washed with water (100 ml), brine (100 ml), dried over sodium sulfate, concentrated and purified by silica gel column chromatography to give 8.5 g of 6-[2-ethyl-5-(2S,3S,4R,5R,6R)-3,4,5-tris-benzyloxy-6-trityloxymethyl-tetrahydro-pyran-2-yl)-benzyl]-2,3-dihydro-benzo[1,4]dioxine as a colorless oil.

1. customreaction mixture
2. temperaturewas cooled to 0° C.
3. customto attain room temperature
4. stirringstirred for overnight
5. customReaction mixture
6. additionwas poured into ice cold water
7. extractionextracted with ethyl acetate (2×80 ml)
8. washCombined organic layers were washed with water (100 ml), brine (100 ml)
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated
11. custompurified by silica gel column chromatography

ORD record

ord-9626c5cc5d024f14af5d83eeea6e5cf8

Source dataset

uspto-grants-2013_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08614195B2