Synlett 2003(8): 1153-1154
DOI: 10.1055/s-2003-39898
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of Isocyano Peptides by Dehydration of the N-Formyl Derivatives

Gang Zhaoa, Carine Bughina, Hugues Bienayméb, Jieping Zhu*a
a Institut de Chimie des Substances Naturelles, CNRS, 91198 Gif-Sur-Yvette Cedex, France
Fax: +33(1)69077247; e-Mail: zhu@icsn.cnrs-gif.fr;
b Chrysalon, 11 Avenue Albert Einstein, 69100 Villeurbanne, France
Further Information

Publication History

Received 4 April 2003
Publication Date:
11 June 2003 (online)

Abstract

Phosphoryl chloride in combination with triethylamine dehydrates N-formyl peptides to provide the corresponding iso­cyano peptides in excellent yields.

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Compound 4: Rf = 0.43 (EtOAc/heptane = 1/1); [α]D = +13.8 (c 0.3, CHCl3). IR (CHCl3): ν = 3422, 2138, 1744, 1684, 1603, 1522, 1497, 1437, 1363, 1180 cm-1.
1H NMR (250 MHz, CDCl3, ppm): δ = 3.08-3.30 (m, 4 H), 3.69 (s, 3 H,), 4.37 (dd, J = 4.5 Hz, 7.3 Hz, 1 H), 4.84 (dt, J = 5.7 Hz, 7.8 Hz, 1 H), 6.73 (d, J = 5.7 Hz, 1 H), 7.20-7.33 (m, 10 H). 13C NMR (62.5 MHz, CDCl3, ppm): δ = 37.6, 38.3, 52.4, 53.1, 59.4, 127.3, 127.6, 127.7, 129.6, 129.0, 134.4, 134.8, 164.1, 170.7. MS (EI): m/z = 336 (M+), 227, 245. Anal. Calcd for C20H20N2O3: C, 71.43; H, 5.95; N, 8.33. Found: C, 71.44; H, 5.98; N, 8.30. Compound 6: Rf = 0.48 (EtOAc/heptane = 1/1.5); [α]D = +17.5 (c 0.5, CHCl3). IR (CHCl3): ν = 3421, 3012, 2138, 1745, 1685, 1603, 1521, 1497, 1455, 1362, 1210, 1280, 1120 cm-1. 1H NMR (250 MHz, CDCl3, ppm): δ = 3.00-3.30 (m, 4 H), 3.72 (s, 3 H), 4.35 (dd, J = 4.2 Hz, 7.8 Hz, 1 H), 4.84 (dd, J = 6.7 Hz, 12.7 Hz, 1 H), 6.72 (d, J = 6.7 Hz, 1 H), 7.15-7.32 (m, 10 H). 13C NMR (62.5 MHz, CDCl3, ppm): δ = 37.8, 38.9, 52.6, 53.6, 59.9, 127.5, 127.8, 128.8, 129.2, 129.5, 134.7, 135.2, 164.7, 170.9. MS (EI): m/z = 336 (M+), 277, 245. Anal. Calcd for C20H20N2O3: C, 71.43; H, 5.95; N, 8.33. Found: C, 69.92; H, 6.05; N, 8.15.