Phenethyl bromide → (S)-Dimethyl (3-methyl-2-oxo-5-phenylpentyl)phosphonate

Participants

Reaction Steps

(S)-Dimethyl (3-methyl-2-oxo-5-phenylpentyl)phosphonate was prepared in the same manner as the second alternative preparation of (S)-(+)-dimethyl (3-methyl-2-oxo-6-phenylhexyl)phosphonate (15mb(i)) using the same sequence of reactions except that (2-bromoethyl)benzene was used instead of (3-bromopropyl)benzene. The crude product was purified by silica gel chromatography. Elution with ethyl acetate-heptane (50:50 v/v) afforded the title compound (460 mg) as a colorless oil; TLC Rf 0.14 (solvent system: 50:50 v/v ethyl acetate:heptanes); MS (ESI+) m/z 285.1 (M+H)+; 1H-NMR (CDCl3) δ 7.30-7.24 (m, 2H), 7.21-7.14 (m, 3H), 3.76 (d, J=14.65 Hz, 3H), 3.76 (d, J=8.06 Hz, 3H), 3.16-3.03 (m, 2H), 2.77 (q, J=6.84 Hz, 1H), 2.64-2.56 (m, 2H), 2.03 (ddt, 1H), 1.16 (d, J=6.96 Hz, 3H); [α]Tλ=α/cl, [α]21.9D=0.052/(0.01998 g/1.5 mL)(0.5)=+7.81° (c=1.33, CHCl3).

Provenance & Evidence