Triphenylphosphine → (2S)-3-[4-(3-Bromopropoxy)-phenyl]-2-methoxy-propionic acid ethyl ester

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Reaction Steps

A solution of triphenylphosphine (4.77 mmol, 1250 mg) in 50 mL of dry toluene was treated at 0° C. with diisopropilazodicarboxylate (4.77 mmol, 964.5 mg) and stirred for about 20 minutes. A solution of (2S)-3-(4-hydroxy-phenyl)-2-methoxy-propionic acid ethyl ester (Example 283, Step 1) (4.46 mmol, 1000 mg) and 3-bromo-propan-1-ol (4.77 mmol, 663 mg) in 10 mL of dry THF was added, and the mixture was stirred at room temperature overnight. The mixture was concentrated to dryness under vacuum and purified by silica gel chromatography (silica gel, hexanes/ethyl acetate 6:1). The fraction with Rf 0.4 corresponding to the coupled compound was combined and concentrated to dryness to afford a yellow oil. MS (ES) for C15H21BrO4 [M+Na]+: 367.2.

Provenance & Evidence