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

2;
H2
See General Procedure for Removal of Roteding Groups.
[al2OD = +34.0 (c = 0.71, 6 N HCI), (lit? [a120D = +34.7 (c = 0.79, 6 N HCI)); 'H NMR
(&O, 300 MHz) 6 3.84-3.76 (m, IH, a-CH), 2.70-2-6 1 (m. lH, y€@, 2.12-2.0 1 (m. lH,
$-CHH), 1.93- 1.84 (m, 1 H, $-CHH), 1.12 (t, 3H. J = 6.8 Hz, fl-CH3); I3c NMR (w, 75
MHz) 6 183.5 175.0 CC), 55.0 (a -, 39.1 ($--a2), 36.6 (y-, 19.6 (y-
- CH3); ESI-MS (M + 16 1.9 1. Anal. cdcd for C&XlzNO4Cl: C, 36.47; H, 6.12; N, 7.09.
Found: C, 36.72; H, 6.32; N, 7.19.
4*4*45 (2S,4S)-2-Amin0-4~tby1pentrnedioic acid, (2S,4S)-EthylglutPmic acid, 4.3*
See General Procedure for Removal of Protecting Groups.
[al2Oo = +23.0 (c = 0.78,6N HCl) (lit? [a120D = +28.4 (c = 1.OY6N HCl)); TU3 (1 : 1 : 1 : 1,
EtOAc:HsO:nBuOH:AcOH), Rr = 0.75; 'H NMR (DS, 300 MHz) S 4.08-3.84 (m, IH, a-
cm, 2.62-2.44 (m, lH, y-CH), 2.12-2.00 (m, lH, P-CHH). 1.98-1.85 (m. lH, p-Cm
1 S8- 1.45 (m, 2H, CH-i), 0.77 (t, 3H, J = 7.3Hz. CH2CH3); 13c NMR (&O. 75 MHz)
6 183.8 Cs), 175.1 @O), 54.0 (a-CH). 47.5 (y-), 33.7 ($-CH2), 25.4 =CH3),
10.9 (CH&&); ESI-MS (M + H+) 176.30. Anal. calcd for CiHl&T04CI : C, 39.73; H,
6.67; N, 6.62. Found: C, 40.1 1; H, 6.99; N, 6.75.