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

I
C-O), 7 1.9 (OB0 ester GHzO), 61.7 (B--H), 57.9 (a---, 29.9 (OB0 ester sH3), 13.9
(OB0 ester CCH3); ESI-MS (M + H') 189.93; Anal. calcd for CsHia04: C, 50.78; H,
7.99; N, 7.40. Found: C, 50.99; H, 8.23; N, 7.47.
6.4.4 (2S~R)-2-Amin011-(2,6,7-tri0~8bicycïo[2.2.2]~t-1-y1)prop~-3~1, Thr-OB0
ester, 6.27.
Cbz-Thr-OB0 ester 6.25 (6.1 1 g, 18.1 1 mmol) was dissolved in Et0Ac:EtOH (1 : 1, 100
mL) to which Pd/C (2 g) was added. The mixture was evacuated, purged with Hz,
evacuated once more then purged with H2 and ailowed to stir ovemight. The solution
was filtered through Celite and the filtrate reduced in vacuo to reveal 3.63 g (99% yield)
of a yellow oil that solidified upon standing.
[al2'o = -5.8 (c = 1.09, EtOH); TU: (9: 1 Et0Ac:MeOH) Rf= 0.34; NMR (DMSO-&,
250 MHz) 6 4.12 (m, 1& P-CH), 3.81 (S. 6H. OB0 ester CHG), 2.59 (d, lH, J = 8.4Hz,
a-CH), 1.22 (d, 3H, J = 6.7Hz. B-CH3), 0.79 (s, 3H, OB0 ester CCH3); 13c NMR
@MSO-Q, 63 MHz) 6 1 08.1 (OB0 ester Ç-O), 7 1.9 (OB0 ester CH20), 64.7 @-CH).
58.9 (a-CH), 29.9 (OB0 ester WH3). 18.3 (B-m3), 13.9 (OB0 ester CCH3); ESI-MS
(M + H+) 203.84; Anal. caicd for C9HiïN04: C, 53.19; H, 8.43; N, 6.89. Found: C.