Benzyl Bromide → (S)-(+)-dimethyl (3-methyl-2-oxo-4-phenylbutyl)phosphonate

HRID 59704Notes

Reaction equation

HRID 59704 reaction equation
[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]

Participants

3

Reactant 2

HCID 7498Benzyl BromideHCID 90054415dimethyl(S)-(3-methyl-2-oxo-6-phenylhexyl)phosphonate

Product 1

HCID 57614980(S)-(+)-dimethyl (3-methyl-2-oxo-4-phenylbutyl)phosphonate

Procedure

(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).

Workup

  1. customThe crude product was purified by silica gel chromatography
  2. washElution with ethyl acetate-heptane (80:20 v/v)

Sources & evidence

ORD record
ord-69a3d34b25174afe9acc510af5e3e5bc
Source dataset
uspto-grants-2016_09
Patent number
US09440919B2

Reaction notes

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