p-Toluenesulfonic acid → (4S)-N-Boc-4-phenylmethyloxazolidin-5-one

Participants

Reaction Steps

(4S)-4-Benzyl-N-tert-butyloxycarbonyl-1,3-oxazolidin-5-one (1) was prepared from N-tert-butyloxycarbonyl-(L)-phenylalanine (2.65 g, 10.0 mM) and para-toluene-sulfonic acid (30 mg) following general procedure A and obtained as a white solid after crystallisation from diethyl ether (1.49 g, 54%): [α]D20 +23.5 (c 1.0, CHCl3); mp 84-86° C.; IR (KBr): 1795, 1705 cm-1 ; 1H NMR (500 MHz, d8 -toluene, 90° C.): δ 6.97-7.08 (m, 5H), 4.75 (d, J=4 Hz, 1H), 4.03-4.05 (m, 2H), 3.17 (dd, J=4, 14 Hz, 1H), 2.92 (dd, J=3, 14 Hz, 1H), 1.31 (s, 9H); 13C NMR (50.3 MHz, CDCl3): 6 172.7, 153.2, 135.0, 129.8, 128.9, 127.6, 82.0, 78.0, 56.3, 34.3, 28.6; LRMS (NH3): 295 (MNH4+). Anal. Calcd for C15H19NO4 : C, 64.96; H, 6.90; N, 5.05; found: C, 64.93; H, 6.73; N, 4.83.

Provenance & Evidence