Benzyl Bromide → (2S,4R)-2-benzyloxymethyl-4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine

Participants

Reaction Steps

R2—ether formation: To a slurry of sodium hydride (60% in mineral oil, 2.75 g) in DMSO (100 ml) were added (2S,4R)-[4-tert-butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidin-2-yl]-methanol (11.2 g) in portions within 0.5 h and benzyl bromide (7.2 ml) dropwise within 0.5 h at 20° C. The reaction mixture was stirred at room temperature for 1.5 h, poured onto ice/water and extracted with EtOAc. The organic phases were washed with water and brine, dried over magnesium sulphate and concentrated. The residue was crystallized from acetone/Et2O/hexane to obtain (2S,4R)-2-benzyloxymethyl-4-tert -butoxy-1-(naphthalene-2-sulfonyl)-pyrrolidine (10.05 g) as a colorless solid, mp 101–103° C., MS: 454 (MH+).

Provenance & Evidence