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which was immediately used in the Claisen rearrangement step.
Boc
N
H
Bn
O
64a
2-tert-Butoxycarbonylamino-3-phenylpropionic acid 1-hexylbut-2-ynyl ester (64a). Prepared
by following general procedure C, using: dec-2-yn-4-ol (200 mg, 1.29 mmol), DMAP (15 mg,
0.12 mmol), DCC (267 mg, 1.29 mmol), N-Boc-phenylalanine (344 mg, 1.29 mmol). Yield of
64a (458 mg, 88%).
CbzHN
2-Benzyloxycarbonylaminopropionic acid 1-methylprop-2-ynyl ester (64c). Prepared by
following general procedure C, using: 3-butyn-2-ol (165 µL, 2.24 mmol), DMAP (12 mg, 0.098
mmol), DCC (462 mg, 2.24 mmol) and N-Cbz-alanine 62c (500 mg, 2.24 mmol). Yield of 64c
(600 mg, 97%).
1 H NMR (300 MHz, CDCl3): δ 7.34-7.27 m (5H), 5.53-5.45 (m, 2H), 5.11 (s, 2H), 4.45-4.35 (m,
1H), 2.50-2.45 (m, 1H), 1.53-1.48 (m, 3H), 1.43-1.39 (m, 3H); 13 C NMR (75 MHz, CDCl3): δ
171.7, 155.4, 136.1, 128.3, 127.9, 81.3, 81.2, 73.5, 73.3, 66.7, 61.0, 49.5, 49.4, 20.9, 18.3.
Cbz
TMS
N
H
64d
2-Benzyloxycarbonylaminopropionic acid 1-methyl-3-trimethylsilylprop-2-ynyl ester (64d).
Prepared by following general procedure C using: 4-trimethylsilylbut-3-yn-2-ol (600 mg, 4.22
mmol), DMAP (51 mg, 0.42 mmol), DCC (956 mg, 4.64 mmol), N-Cbz-alanine (988 mg, 4.43
O
O
64c
O
155
C 6H 13
O
O