(5-Bromopentyl)benzene → (S)-(+)-dimethyl (3-methyl-2-oxo-8-phenyloctyl)phosphonate

Participants

Reaction Steps

(S)-Dimethyl (3-methyl-2-oxo-8-phenyloctyl)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 (5-bromopentyl)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 (1.06 g) as a colorless oil; TLC Rf 0.22 (solvent system: 50:50 v/v ethyl acetate:heptanes); MS (ESI+) m/z 327.1 (M+H)+; 1H-NMR (CDCl3) δ 7.27-7.24 (m, 2H), 7.19-7.14 (m, 3H), 3.79-3.76 (m, 6H), 3.13 (s, 1H), 3.08 (s, 1H), 2.76-2.68 (m, 1H), 2.61-2.56 (m, 2H), 1.68-1.56 (m, 4H), 1.35-1.28 (m, 4H), 1.09 (d, J=6.96 Hz, 3H); [α]Tλ=α/cl, [α]21.9D=0.074/(0.01534 g/1.5 mL)(0.5)=+14.10° (c=1.02, CHCl3).

Provenance & Evidence