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

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

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

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ester COI3), 30.6 (p-cH2), 14.1 (OB0 ester CDS); IR (cast from CHC13) 3362, 2953,<br />

2882,1734, 1520,1456, 1399, 1352, 1293,2133,1052; HRMS (FAB) calcd for (M + H+)<br />

C18H2m 366.15527, found 366.15538; And. cdcd for Cl&I*&: C, 59.17; H, 6.34;<br />

N, 3.83. Found: C, 59.33; H, 6.58; N, 3.87.<br />

5.4.6 44 ert-ButyE(2S}-2-[(bell~yloxy)carbonyl]~<br />

bicyclo[2.2.2]oct-1-yl)butanoate, Cbz-L-Asp(0tBu)OBO ester, 5.39.<br />

Sarne procedure as in section 5.4.5 to give 7.35 g (68.196) <strong>of</strong> 5.39. m.p. 77-78°C; [alZoD<br />

= -4.8 (c = 1.36, CH2C12); TLC (1:1, EtOAc:Hex), Rf = 0.45; 'H NMR (CDC13, 250<br />

MHz) 8 7.32-7.22 (m. SH, ArH), 5.97 (d, 1 H, J = 8.8Hz, NH), 5.06 (s, 2H, CbzCH?),<br />

4.594.51 (dt, lH, J = 4.8,8.8Hz, a-CH), 3.81 (s, 6H, OB0 ester C m), 2.87 (dd, lH, J<br />

= 4.8, 17.1H2, P-CHH), 2.72 (dd, lH, J = 4.8, 17.1Hz. p-CHH), 1.36 (s, 9H, (CH3)3C),<br />

0.77 (S. 3H, OB0 ester CC&); "C NMR (ml3, 63 MHz) 6 170.1 (C=O), 156.1<br />

(CONH), 135.9 (Cbz*), 128.3, 128.0, 127.9 (Cbz=QI=), 107.9 (OB0 ester C-O),<br />

8 1.9 ((CH3)1C), 72.4 (OB0 ester w), 66.9 (CbzCH20), 50.5 (a-CH), 40.5 (OB0 ester<br />

CCH3), 37.4 (B-CH2), 16.5 (OB0 ester Cc&); And. calcd for CZIH~~N~: C, 61.90; H,<br />

7.17; N, 3.44. Found: C, 62.23; H, 7.39; N, 3.96.

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