1-Bromo-4-phenylbutane → (S)-Dimethyl (3-methyl-2-oxo-7-phenylheptyl)phosphonate

Beteiligte Stoffe

Reaktionsschritte

(S)-Dimethyl (3-methyl-2-oxo-7-phenylheptyl)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 (4-bromobutyl)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 (2.84 g) as a colorless oil; TLC Rf 0.54 (solvent system: 100 v ethyl acetate); MS (ESI+) m/z 313.1 (M+H)+; 1H-NMR (CDCl3) δ 7.22-7.17 (m, 2H), 7.12-7.07 (m, 3H), 3.82-3.68 (m, 6H), 3.07 (s, 1H), 3.01 (s, 1H), 2.71-2.62 (m, 1H), 2.53 (t, J=7.69 Hz, 2H), 1.66-1.47 (m, 4H), 1.28-1.22 (m, 2H), 1.02 (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=1.017, CHCl3).

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