Benzyl Bromide → (S)-(+)-dimethyl (3-methyl-2-oxo-4-phenylbutyl)phosphonate
Reaktionsgleichung
[CH3:1][C@@H:2](CCCC1C=CC=CC=1)[C:3](=[O:11])[CH2:4][P:5](=[O:10])([O:8][CH3:9])[O:6][CH3:7].[CH2:21](Br)[C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1>>[CH3:1][C@@H:2]([CH2:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)[C:3](=[O:11])[CH2:4][P:5](=[O:10])([O:6][CH3:7])[O:8][CH3:9]Komponenten
3
Versuchsvorschrift
(S)-(+)-Dimethyl (3-methyl-2-oxo-4-phenylbutyl)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 benzyl bromide was used instead of (3-bromopropyl)benzene. The crude product was purified by silica gel chromatography. Elution with ethyl acetate-heptane (80:20 v/v) afforded the title compound (680 mg) as a colorless oil; TLC Rf 0.35 (solvent system: 80:20 v/v ethyl acetate:heptanes; MS (ESI+) m/z 271.1 (M+H)+; 1H-NMR (CDCl3) δ 7.29-7.14 (m, 5H), 3.71 (dd, 6H, J=10.99, 19.04 Hz), 3.12-2.89 (m, 4H), 2.58 (dd, 1H, J=7.69, 13.55 Hz), 1.11 (d, 3H, J=6.96 Hz); [α]Tλ=α/cl, [α]21.9D=0.249/(0.01501 g/1.5 mL)(0.5)=+49.8° (c=1, CHCl3).