M. A. Brimble, M. Trzoss / Tetrahedron 60 (2004) 5613–5622
5621
(8–12 h). In some cases further addition of scandium(III)-
triflate (20 mg, 0.04 mmol) after 6 h was necessary to obtain
complete reaction. The reaction mixture was evaporated
under reduced pressure and the Boc-protected allylated
amine was obtained after purification of the residue by
column chromatography using hexane/ether 10:2 as eluant.
3.8.2. 7-Allyl-8-azaspiro[5.6]dodec-2-ene (35). 84%
Yield; colorless oil (mixture of diastereomers);† IR nmax
/
cm21 3019, 2925, 2854, 1448, 1438, 1152, 992, 913; H
NMR (300 MHz, CDCl3) d 5.83–5.53 (m, 3H), 5.13–5.01
(m, 2H), 3.17–3.02 (m, 1H), 2.58–2.39 (m, 1H), 2.34–2.15
(m, 2H), 2.10–1.22 (m, 14H); 13C NMR (75 MHz, CDCl3)
d 137.6, 137.5, 127.2, 126.3, 125.9, 125.7, 117.2, 117.0,
67.8, 67.6, 52.3, 50.0, 38.1, 37.8, 35.8, 35.4, 35.1, 34.6,
32.7, 32.6, 31.7, 31.5, 29.7, 27.8, 22.9, 21.9, 21.2, 21.15;
MS (EI) m/z 205 (20%, [M]þ), 164 (100); HRMS Calcd for
C14H23N 205.1831; found, 179.1825.
1
3.7.1. tert-Butyl 1-allyl-2-azaspiro[5.5]undec-8-ene-2-
carboxylate (32). 78% Yield; colorless oil (mixture of
diastereomers and rotamers);† IR nmax/cm21 2974, 2930,
1
2863, 1693, 1417, 1364, 1248, 1176, 1159, 1147, 909; H
NMR (300 MHz, CDCl3) d 5.77–5.50 (m, 3H), 5.06–4.93
(m, 2H), 4.12–4.03 (m, 1H), 3.94–3.84 (m, 1H), 2.77–2.62
(m, 1H), 2.51–2.35 (m, 1H), 2.29–1.20 (m, 20H); 13C NMR
(75 MHz, CDCl3) d 155.7, 155.6, 135.9, 135.8, 135.5, 135.4,
126.6, 126.5, 125.9, 125.7, 125.4, 124.3, 124.2, 116.4, 116.3,
115.9, 79.0, 78.9, 78.7, 58.2, 56.9, 54.8, 53.9, 38.9, 38.6, 37.5,
37.1, 36.4, 36.3, 34.1, 34.0, 33.8, 33.6, 33.5, 31.9, 31.3, 30.7,
30.4, 30.3, 30.2, 29.7, 28.6, 28.5, 28.4, 27.3, 26.9, 22.2, 22.1,
21.0, 20.9, 20.6, 20.5; MS (EI) m/z 291 (1%, [M]þ), 194 (100),
150 (34); HRMS (CI) Calcd for C18H30NO2 (MþH)
292.2276; found, 292.2275 ([MþH]þ).
Acknowledgements
We thank the Royal Society of New Zealand Marsden Fund
for financial support of this work.
References and notes
1. Garthwaite, I. Trends Food Sci. Technol. 2000, 11, 235.
2. Seki, T.; Satake, M.; Mackenzie, L.; Kaspar, H. F.; Yasumoto,
T. Tetrahedron Lett. 1995, 36, 7093.
3.7.2. tert-Butyl 7-allyl-8-azaspiro[5.6]dodec-2-ene-8-
carboxylate (33). 70% Yield; colorless oil (mixture of
diastereomers and rotamers);† IR nmax/cm21 2973, 2927,
2865, 1688, 1414, 1364, 1166, 1135, 909; 1H NMR
(300 MHz, CDCl3) d 5.83–5.48 (m, 3H), 5.06–4.92 (m,
2H), 4.33–4.20 and 4.03–3.90 (each m, 1H), 3.79–3.46 (m,
1H), 2.97–2.76 (m, 1H), 2.38–1.17 (m, 23H); 13C NMR
(75 MHz, CDCl3) d 156.7, 156.4, 156.2, 136.8, 136.4,
136.3, 136.0, 135.8, 135.6, 135.5, 126.8, 126.7, 125.9,
125.8, 125.7, 124.8, 124.7, 116.6, 116.4, 116.3, 116.2,
116.0, 115.9, 79.1, 79.0, 78.6, 63.0, 61.4, 58.5, 58.0, 41.6,
41.2, 41.0, 40.9, 39.3, 39.1, 38.4, 37.4, 36.9, 36.5, 35.1,
34.2, 34.1, 32.8, 32.2, 32.0, 31.4, 31.3, 31.1, 30.8, 30.7,
30.4, 30.3, 29.7, 29.5, 29.2, 29.0, 28.6, 28.5, 28.3, 27.5,
26.7, 26.1, 26.0, 22.5, 22.4, 22.3, 20.7, 20.3, 20.1, 19.9; MS
(EI) m/z 305 (1%, [M]þ), 208 (100), 57 (95); HRMS Calcd
for C19H31NO2 305.2355; found, 305.2357.
3. Lu, C. K.; Lee, G. H.; Huang, R.; Chou, H. N. Tetrahedron
Lett. 2001, 42, 1713.
4. Hu, T. M.; Curtis, J. M.; Oshima, Y.; Quilliam, M. A.; Walter,
J. A.; Watsonwright, W. M.; Wright, J. L. C. J. Chem. Soc.,
Chem. Commun. 1995, 2159.
5. Hu, T. M.; Curtis, J. M.; Walter, J. A.; Wright, J. L. C.
Tetrahedron Lett. 1996, 37, 7671.
6. Hu, T. M.; Burton, I. W.; Cembella, A. D.; Curtis, J. M.;
Quilliam, M. A.; Walter, J. A.; Wright, J. L. C. J. Nat. Prod.
2001, 64, 308.
7. Cembella, A. D.; Lewis, N. I.; Quilliam, M. A. Nat. Toxins
1999, 7, 197.
8. Uemura, D.; Chou, T.; Haino, T.; Nagatsu, A.; Fukuzawa, S.;
Zheng, S. Z.; Chen, H. S. J. Am. Chem. Soc. 1995, 117, 1155.
9. Chou, T.; Kamo, O.; Uemura, D. Tetrahedron Lett. 1996, 37,
4023.
3.8. General procedure for the Boc-deprotection
10. Takada, N.; Umemura, N.; Suenaga, K.; Uemura, D.
Tetrahedron Lett. 2001, 42, 3495.
To a stirred solution of the Boc-protected amine (0.3 mmol)
in DCM (3 mL) was added TFA (3 mL). After stirring
for 30 min at 23 8C toluene (20 mL) was added and the
reaction mixture evaporated under reduced pressure. The
spiroamine was obtained after purification of the residue by
column chromatography using hexane/DCM/MeOH/Et3N
10:20:4:0.2 as eluant.
11. Stewart, M.; Blunt, J. W.; Munro, M. H. G.; Robinson, W. T.;
Hannah, D. J. Tetrahedron Lett. 1997, 38, 4889.
12. Ahn, Y.; Cardenas, G. I.; Yang, J.; Romo, D. Org. Lett. 2001,
3, 751.
13. Tsujimoto, T.; Ishihara, J.; Horie, M.; Murai, A. Synlett 2002,
399.
14. Yang, J.; Cohn, S. T.; Romo, D. Org. Lett. 2000, 2, 763.
15. Ishihara, J.; Horie, M.; Shimada, Y.; Tojo, S.; Murai, A.
Synlett 2002, 403.
3.8.1. 1-Allyl-2-azaspiro[5.5]undec-8-ene (34). 90%
Yield; colorless oil (mixture of diastereomers);† IR nmax
/
16. White, J. D.; Wang, G. Q.; Quaranta, L. Org. Lett. 2003, 5,
4109.
cm21 3019, 2927, 2844, 1451, 1435, 1313, 1132, 913, 758;
1H NMR (300 MHz, CDCl3) d 5.78–5.68 (m, 1H), 5.64–
5.55 (m, 2H), 5.12–5.04 (m, 2H), 3.04–2.98 (m, 1H), 2.62–
2.54 (m, 1H), 2.41–2.24 (m, 2H), 2.13–1.12 (m, 11H),
1.01–0.87 (m, 1H); 13C NMR (75 MHz, CDCl3) d 137.2,
137.1, 126.1, 125.9, 125.8, 125.3, 117.5, 117.3, 64.9, 62.5,
47.0, 46.5, 35.6, 34.0, 33.9, 33.1, 31.7, 31.4, 27.2, 23.4,
22.4, 22.2, 22.0; MS (EI) m/z 192 (30%, [MþH]þ), 150
(100); HRMS (CI) Calcd for C13H22N (MþH) 192.1752;
found, 192.1751 ([MþH]þ).
17. Wang, J.; Sakamoto, S.; Kamada, K.; Nitta, A.; Noda, T.;
Oguri, H.; Hirama, M. Synlett 2003, 891.
18. McCauley, J. A.; Nagasawa, K.; Lander, P. A.; Mischke, S. G.;
Semones, M. A.; Kishi, Y. J. Am. Chem. Soc. 1998, 120, 7647.
19. Trzoss, M.; Brimble, M. A. Synlett 2003, 2042.
20. Davis, B. G.; Maughan, M. A. T.; Chapman, T. M.; Villard, R.;
Courtney, S. Org. Lett. 2002, 4, 103.
21. Pradhan, S. K.; Akamanchi, K. G.; Divakaran, P. P.; Pradhan,
P. M. Heterocycles 1989, 28, 813.