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

= l2JHz, CbzCHHO), 3.87-3.78 (s + rn, 7H, OB0 ester C&O, a-CH), 3.55 (s, 3H,
co2cH3), 2.60-2.48 (m, lH, WH), 2.10-2.00 (m. 1H. 8-CHH), 1.45 (ddd, 1H, J = 3.9,
10.7, 14.5- B-Cm, 1.16 (d, 3H, J = 7.3H.2, yCH3), 0.78 (s, 3H, OB0 ester CCH3);
"C NMR (Acetone*, 75 MHz) 6 176.4 c=O), 156.3 GONH), 135.1 (Cbze), 128.3,
127.6, 127.6 (Cbz-a=), 108.8 (OB0 ester -O), 72.3 (OB0 ester w), 65.6
(CbzGH20), 53.3 (a--), 50.8 (COa3), 35.7 (yCH), 33.5 (OB0 ester Ca3), 30.3 (p-
- CH3, 17.6 (y-CH3), 13.4 (OB0 ester CcH3); And. calcd for CZ&InNq: C, 61 .O6; H,
6.84; N, 3.56. Found: C, 61.29; H, 7.01; N, 3.66.
4.4.13 5-Methyl-(2R,~)-2-[(be~1zylo~1y)caibonyl]~~-m~yl-1-(4me~yl-2,6,7-
trhxa-bicyclo[2.2.2]0~t-1-yl)pentanoate, Cbz-D-Glu(yMe)(OMe)-OB0 ester, 4.75
Sarne procedure as in 4.4.1 1. [a120D = +24.3 (c = 1.1, CH2C12); TU3 (1:1, EtOAc:Hex),
Rf = 0.59; 'H NMR (Acetone-a, 300 MHz) 6 7.38-7.26 (m, SH, ArH), 5.71 (d, lH, J =
9.8H.2, NH), 5.10-5 .O0 (m, SH, CbzC&O), 3.89 (s, 6H, OB0 ester Cao), 3.90-3.82 (m,
lH, a-Cm, 3.55 (s, 3H, CO2CH,), 2.49-2.28 (m. IH, yCH), 1.88- 1.64 (m, 2H, $-Ca),
1.10 (d, 3H, J = 6.7Hz, y-CH3). 0.78 (s, 3H. OB0 ester CCH3); 13c NMR (Acetone-6,
75 MHz) 6 176.5 cd), 156.4 (CONH), 137.6 (Cbz=c=), 128.3, 127.7, 127.7
(Cbzq=), 108.3 (OB0 ester C-O), 72.4 (OB0 ester m), 65.8 (Cbzw20), 53 .O (a-
-
CH), 50.9 (COcH3), 35.9 (y-CH), 33.3 (OB0 ester CCH3), 30.3 @--), 15.8 (y-CH3),