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Deprotection of (t-Boc) with Sn(OTf )2
REFERENCES
. (a) Greene, T.W.; Wuts, P.G.M. Protective Groups in Organic
449
1
Synthesis, 2nd Ed.; John Wiley & Sons: New York, 1991; (b)
Kocienski, P.J. Protecting Groups; Georg Thieme Verlag: Stuttgart,
1994.
2
3
. (a) Schwyzer, R.; Costopanagiotis, A.; Sieber, P. Helv. Chim. Acta
1963, 46, 870; (b) Sakai, N.; Ohfune, Y.J. J. Am. Chem. Soc. 1992,
114, 998.
. (a) Stahl, G.L.; Walter, R.; Smith, C.W. J. Org. Chem. 1978, 43,
285; (b) Houghten, R.A.; Beckman, A.; Ostresh, J.M. Int. J. Pept.
2
Protein Res. 1986, 27, 653; (c) Yamashiro, D.; Blake, J.; Li, C.H.
J. Am. Chem. Soc. 1972, 94, 2855; (d) Shaikh, N.S.; Gajare, A.S.;
Deshpande, V.H.; Bedekar, A.V. Tetrahedron Lett. 2000, 41, 385.
. (a) Bose, D.S.; Lakshminarayana, V. Synthesis 1999, 66; (b) Nigam,
S.C.; Mann, A.; Taddei, M.; Wermuth, C.-G. Synth. Commun. 1989,
4
5
19, 3139.
. (a) Hwu, J.R.; Jain, M.T.; Tsay, S.-Ch.; Hakimelahi, G.H.
Tetrahedron Lett. 1996, 37, 2035; (b) Wei, Z.-Y.; Knaus, E.E.
Tetrahedron Lett. 1994, 35, 847; (c) Boeckman, R.K., Jr.; Potenza,
J.C. Tetrahedron Lett. 1985, 26, 1411.
6. Rawal, V.H.; Cava, M.P. Tetrahedron Lett. 1985, 26, 6141.
7. Thurston, D.E.; Bose, D.S. Chem. Rev. 1994, 94, 433.
8. Paquette, L.A. Encyclopedia of Reagents for Organic Synthesis; Joh n
Wiley & Sons: Chichester, 1995; Vol. 7, 4907.
9
. Selected analytical data: compounds 1a, 1b, 2a, 2f isolated as amine
ꢁ
1
hydrochloride salts. 1a: [ꢀ] ¼ À45.0 (c 0.53, CHCl3), H NMR
D
(
(
(
(
CDCl ) ꢁ 1.45 (s, 9H), 1.85–2.05 (m. 4H), 3.38–3.60 (m, 2H), 3.75
3
ꢁ
1
s, 3H), 4.16–4.36 (m, 1H). 1b: [ꢀ] ¼ À49.5 (c 3.4, CHCl ), H NMR
D
3
CDCl ) ꢁ 1.45 (s, 9H), 1.50 (s, 9H), 1.81–1.98 (m, 3H), 2.15–2.30
3
m, 2H), 3.38–3.58 (m, 2H), 4.10 (dd, 1H, J ¼ 3.4, 8.9). Anal. calcd.
for C H NO : C, 61.7; H, 9.6; N, 5.1. Found: C, 61.5; H, 9.6; N,
1
5.2. 2a: m.p. 68–70 C (lit.
H O), lit.
4
26
4
ꢁ
[11]
ꢁ
m.p. 69–71 C); [ꢀ] ¼ À31.0 (c 0.5,
D
[11]
ꢁ
ꢁ
[12]
[ꢀ] ¼ À33 Æ 2 (c 0.5, H O). 2b: m.p. 108–109 C
2
D
2
[
13]
ꢁ
(
lit.
m.p. 109–111 C); [ꢀ] ¼ À30.0 (c 1.2, EtOH), lit.
D
ꢁ
[
1
ꢀ] ¼ À31.0 (c 2.0, EtOH), Anal. calcd. for C H NO: C, 69.6; H,
D
9
17
ꢁ
[11]
1.0; N, 9.0. Found: C, 69.0; H, 10.6; N, 8.7. 2c: m.p. 58–59 C (lit.
ꢁ
1
m.p. 57–60 C); 1d: [ꢀ] ¼ þ13.5 (c 1.0, CHCl ). H NMR (CDCl ) ꢁ
D
3
3
1
1
.45 (s, 9H), 3.54–3.70 (m, 2H), 3.95–4.01 (m, 2H), 4.72–4.88 (bs,
H), 5.12–5.31 (m, 2H), 5.75–5.94 (m, 1H), 7.22–7.35 (m, 5H). 2d:
[
ꢀ] ¼ þ 24.5 (c 1.0, CHCl3). Anal. calcd. for C H NO;
D
11 15