Acetone → (R)-2-(5-Bromo-2-fluoro-phenoxymethyl)-oxirane

Reaction equation

[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:9])=[C:6]([OH:8])[CH:7]=1.C(=O)([O-])[O-].[K+].[K+].[CH3:16][C:17]([CH3:19])=[O:18]>>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([F:9])=[C:6]([CH:7]=1)[O:8][CH2:16][C@H:17]1[CH2:19][O:18]1

Participants

Reactant 3

HCID 180Acetone

HCID 11430Potassium Carbonate

HCID 183421Phenol, 5-bromo-2-fluoro-

Product 1

HCID 86603895(R)-2-(5-Bromo-2-fluoro-phenoxymethyl)-oxiraneYield 82%

Procedure

A solution of the crude 5-bromo-2-fluorophenol (4.0 g) prepared using literature procedure [EP0238272] and (2R)-glycidyl 3-nitrobenzenesulfonate (5.37 g) in dry acetone (175 mL) was treated with potassium carbonate (8.58 g) and refluxed under nitrogen for 12 h. The reaction was cooled, filtered and filtrate was concentrated in vacuo and the residue was flash chromatographed (20% ethyl acetate/hexanes) to yield the desired product (4.25 g) in 82% yield. 1H NMR (400 MHz, CDCl3): δ 7.15-6.96 (m, 3H), 4.33 and 4.30 (dd, 1H), 4.02 and 4.00 (dd, 1H), 3.41-3.37 (m, 1H), 2.97 (m, 1H), 2.78 (m, 1H).