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

4-4-46 (2S,4S)-2-My14aminopentanedioic ad& (2S,4S)-AU y1ghatamic acid, 4.81.
See General Procedure for Removal of Protecting Groups using 1N HCl.
[alZ0D = +36.7 (c = 0.65, 6N HCl); 'H NMR @20, 300 MHz) 6 5.72-5.56 (rn, lH,
CH=CHz), 5.05-4.96 (m, 2H, CH=CH2), 4.07-3.95 (m, 1 H, a-CH), 2.74-2.63 (m, 2H, B-
Cm, y-CH) 2.55-2.44 (rn, lH, &CHH), 2.14- 1.88 (m, 2H, CN2~=CH2); I3c N'R
@*O, 75 Mm) 8 182.8 (C=O), 173.5 c=O), 133.2 (CH=CH2), 1 19.1 (CH--CHâ), 54.1
(a-CH), 4 1 .O (y-CH), 35.4 (p-Hz), 3 1 .O m2CH=CH2); ESI-MS (M + H+) 1 87.85. Anal.
calcd for CsH14N04Cl: C, 42.96; H, 6.3 1 ; N, 6.26. Found: C, 43.29; H, 6.64; N, 6.35.
4.4-47 (ZS,4S)-2-Amin&-be1lzy1pentanedioic acid, (2S,4S)-Benzy1giutamic acid,
4-82.
See General Procedure for Removd of Protecting Groups.
[al2OD = +24A (c = 0.55.6N HCl); 'H NMR p20, 300 MHz) 6 7.28-7.10 (m, SH, Arw,
3.85 (dd, 1 H, J = 5.2,g.O Hz, a-CH), 2.98-2.80 (rn, 3H, y-CH, Arc&), 2.05 (ddd, 1 H, J
= 5.2, 9.8, 14.2 HZ, $-CHH) 1.93 (ddd, l& J = 4.0, 9.0, 14.2 Hz, f3-CI-W); 13c NMR
(DzO, 75 MHz) 6 178.1 cd), 171.7 @O). 137.9 (-=), 129.1, 128.8, 126.8
(m-H=), 5 1.4 (a-ÇH), 43.5 (yQ-I), 38.1 (Ar-Hz), 3 1.5 (DBm2); ESI-MS (M + H+)