Triphenylphosphine → (S)-3-{(S)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-2-[(4-nitro-benzenesulfonyl)-((S)-1-phenyl-propyl)-amino]-propionic acid methyl ester

Participants

Reaction Conditions

Reaction Steps

(S)-3-{(S)-2-[4-(3,4-Dichloro-benzyloxy)-phenyl]-2,3-dihydro-benzo[1,4]dioxin-6-yl}-2-(4-nitro-benzenesulfonylamino)-propionic acid methyl ester (1.6 g) was dissolved in 4 mL dry THF and 1247 mg triphenylphosphine and 650 μL (R)-(+)-1-phenyl-1-propanol were added. The mixture was stirred at 0° C. for 10 min, then 933 μL DIAD was added over 2 min. The reaction stirred at rt for 5 h, then was evaporated. The residue was purified by silica gel flash chromatography (9:1 to 8:2 hexanes/EtOAc) to give 1.8 g desired product after drying. 1H NMR (400 MHz, acetone-d6): 8.35 (m, 2H), 7.96 (m, 2H), 7.72 (d, 1H), 7.62 (d, 1H), 7.51-7.42 (m, 3H), 7.29 (m, 5H), 7.10 (m, 2H), 6.88-6.80 (m, 3H), 5.21 (s, 2H), 5.11 (m, 1H), 4.82 (m, 1H), 4.45 (m, 1H), 4.36 (m, 1H), 4.03 (m, 1H), 3.49 (m, 1H), 3.35 (s, 3H), 3.04 (m, 1H), 2.31 (m, 1H), 1.81 (m, 1H), 0.77 (t, 3H).

Provenance & Evidence