A synthesis of (±)-ipalbidine using sulfur-controlled 6-exo selective radical cyclization of α-phenylthio amide

Heterocycles

Volumn 50, Issue 1, 1999, Pages 31-34

  Ikeda, Masazumi ^a   Shikaura, Jiro ^a   Maekawa, Noriko ^a   Daibuzono, Kaori ^a   Teranishi, Hirotaka ^a   Teraoka, Yoshiko ^a   Oda, Norio ^a   Ishibashi, Hiroyuki ^b  

^a KYOTO PHARMACEUTICAL UNIVERSITY   (Japan)

^b KANAZAWA UNIVERSITY   (Japan)

Author keywords

[No Author keywords available]

Indexed keywords

AMIDE; INDOLIZIDINE ALKALOID; IPALBIDINE; SULFUR DERIVATIVE; UNCLASSIFIED DRUG;

ARTICLE; CHEMICAL STRUCTURE; CYCLIZATION; ISOMERISM; NONHUMAN; PLANT SEED; SYNTHESIS;

EID: 0032864415     PISSN: 03855414     EISSN: None     Source Type: Journal    
DOI: 10.3987/COM-98-S(H)13     Document Type: Article

References (18)

1. J.M. Courley, R.A. Heacock, A.G. McInnes, B. Nikolin, and D.G. Smith, J. Chem. Soc., Chem. Commun., 1969, 709.
2. For reviews on the indolizidine alkaloids, see: J.P. Michael, Nat. Prod. Rep., 1997, 14, 21 and references cited therein.
3. For the synthesis of (±)-ipalbidine, see: (a) T.R. Govindachari, A.R. Sidhaye, and N. Viswanathan, Tetrahedron, 1970, 26, 3829;
4. (b) A.E. Wick, P.A. Bartlett, and D. Dolphin, Helv. Chim. Acta, 1971, 54, 513;
5. (c) R.V. Stevens and Y. Luh, Tetrahedron Lett., 1977, 979;
6. (d) A.S. Howard, G.C. Gerrans, and J.P. Michael, J. Org. Chem., 1980, 45, 1713;
7. (e) H. Iida, Y. Watanabe, and C. Kibayashi, J. Chem. Soc., Perkin Trans. 1, 1985, 261;
8. (f) S.J. Danishefsky and C. Vogel, J. Org. Chem., 1986, 51, 3915;
9. (g) C.W. Jefford, T. Kubota, and A. Zaslona, Helv. Chim. Acta, 1986, 69, 2048;
10. (h) S.M. Sheehan and A. Padwa, J. Org. Chem., 1997, 62, 438.
11. For the asymmetric synthesis of (+)-ipalbidine, see: L. Zhujin, L. Renrong, C. Qi, H. Hai, Acta Chimica Sinica, 1985, 43, 992.
12. 3, 270 MHz) 1.38-2.35 (10 H, m), 3.35-3.45 (1 H, m), 3.55-3.75 (2 H, m), 3.79 (3 H, s, OMe), 3.85-3.98 (1 H, m), 6.85 (2 H, d, J = 8.6 Hz, ArH), 7.13 (2 H, d, J = 8.6 Hz, ArH)].
13. H. Ishibashi, C. Kameoka, H. Iriyama, K. Kodama, T. Sato, and M. Ikeda, J. Org. Chem., 1995, 60, 1276. See also: H. Ishibashi, H. Kawanami, and M. Ikeda, J. Chem. Soc., Perkin Trans. 1, 1997, 817 and references cited therein.
14. H. Ishibashi, C. Kameoka, H. Iriyama, K. Kodama, T. Sato, and M. Ikeda, J. Org. Chem., 1995, 60, 1276. See also: H. Ishibashi, H. Kawanami, and M. Ikeda, J. Chem. Soc., Perkin Trans. 1, 1997, 817 and references cited therein.
15. 3, 270 MHz) spectrum of 13 exhibited the signals due to =CH(SPh) at δ 6.19 (d, J = 14.8 Hz) and 6.28 (d, J = 9.2 Hz) for the (E)-and (Z)-isomers, respectively.
16. 6, 270 MHz) spectrum of 16 exhibited the signals due to 6-H for two stereoisomers at δ 3.56 (d, J = 4.3 Hz) and 3.84 (d, J = 5.6 Hz), respectively.
17. The reason why the α-phenylthio group of 8 did not work as a leaving group is not clear at the moment.
18. It has been reported that (+)-ipalbidine forms hexagonal crystals from benzene/cyclohexane, but the specfic rotation of this material is not reproducible and depends upon the drying conditions because the crystals contain some benzene and cyclohexane. See ref. 3b.