Reaktionsschritte
TentaGel resin was coupled with FmocPhe (Mitsunobu conditions) and reductively alkylated with anisaldehyde. BocSer(OBzl) was coupled with HOAt/DIC and after Boc-deprotection the DKP formed in 4% TEA/toluene (12 h). Yield: 7.1 mg (8.3%). 1H-NMR (400 MHz, CDCl3): δ=1.60 (dd, J=6.4, 6.4 Hz, 1 H), 3.22 (dd, J=3.4, 10.0 Hz, 1 H), 3.28 (dd, J=2.8, 10.0 Hz, 1 H), 3.44 (dd, J=2.2, 6.4 Hz, 1 H), 3.81 (s, 3 H), 3.85 (d, J=14.6 Hz, 1 H), 4.07 (dd, J=2.2, 6.4 Hz, 1 H), 4.18 (dd, J=2.8 3.4 Hz, 1 H), 4.21 (d, J=8.0 Hz, 1 H), 4.25 (d, J=8.0 Hz, 1 H), 5.54 (d, J=14.6 Hz, 1 H), 6.42 (broad s, 1 H), 6.87-6.89 (m, 2 H), 7.19-7.40 (m, 12 H). 13C-NMR (101 MHz, CDCl3): δ=36.6, 46.5, 55.8, 59.0, 72.1, 73.5, 114.6, 126.9, 127.8, 128.0, 128.2, 128.7, 129.1, 130.2, 130.5, 135.2, 137.4, 159.8, 163.5, 166.7. Anal. Calcd. for C27H28 N2O4.2H2O: C, 67.48; H, 6.71; N, 5.83, found: C, 68.00; H, 6.18; N, 5.65.
