Solution and Solid Phase Synthesis of Unusual a-Amino Acids From

TU) ( 1 : 1, CHCl3:EtOAc, 1% AcOHj Rf = 0.14; NMR (CDC13, 3ûûMHz) 6 10.4 (br s,
IH, COOH), 7.32 (br s, 5H, ArH), 6.25 (br s, 1 H, NH), 5.10 (s, 2H, CbzCH20), 44 1 (m,
1 H, a-CH), 3.70 (s, 3H, C@CH3), 2.50-2.3 1 (m, 2H, y-CH2), 2.27-2.10 (m. 1 H, f3-Cm),
2.04-1.84 (m, 1H. B-CHH); 13c NMR (CDC13, 75 MHz) 6 178.1 (CrO), 172.8 @O),
156.1 (CONH), 136.1 (Cbz=C=), 128.6, 128.3, 128.2 (Cbz=CH), 67.3 (Cbz-O), 53.2
(a-CH), 52.7 (com3), 29.9 27.5 (p-a2); MS es0 (M + ~3 296.12.
Same as descnbed in 4.4.3. TLC (1:1, EtOAc:Hex), Rf = 0.35; 'H NMR (CDC13,
300MHz) 6 7.37-7.28 (m, SH, ArH), 5.41 (d, IH, J = 8.3Hz. NH), 5.08 (s, 2H,
CbzCH20), 4.47 (d, 2H, J = 5.9Hz, oxetane ester CHHO), 4.44-4.38 (rn, 1 H, a-CH), 4.35
(d, 2H, J = 5.9Hz. oxetane CHHO), 4.14 (S. 2H, C02CH2), 3.73 (s, 3H, C02CH3), 2.52-
2.38 (m, 2H, y-CHz), 2.28-2.13 (m. lH, B-CHH), 2.06 1 .go (m, 1 H, P-CIW), 1.29 (s, 3H,
oxetane ester CH3); I3c NMR (CDClg, 75 MHz) 6 172.8 C=O), 172.3 (Ç=O), 156.0
(_cQNH), 136.2 (Cbze=), 128.6, 128.2, 128.1 (Cbz