Cyclization of Bicyclic Diterpenes Promoted by SmI₂. Synthesis of Tri- and Tetracyclic Diterpenes

Abstract

The synthesis of 15-hibaen-14-one (a tetracyclic diterpene) is described from zamoranic acid as starting material in an excellent yield and with total control of the stereochemistry. The key step is a SmI₂ promoted pinacol cyclization.

Key words

samarium iodide - stereoselective cyclization - diterpenes - zamoranic acid - hibaenone

References

• 1 Pascual Teresa J. Urones JG. Marcos IS. Díez D. Alvarez VM. Phytochemistry  1986,  25:  711 
• 2a Urones JG. Marcos IS. Gómez-Pérez B. Lithgow AM. Díez D. Basabe P. Gómez PM. Tetrahedron Lett.  1994,  35:  3781 
• 2b Urones JG. Marcos IS. Gómez-Pérez B. Lithgow AM. Díez D. Gómez PM. Basabe P. Garrido NM. Tetrahedron  1995,  51:  1845 
• 3a Urones JG. Marcos IS. Pérez BG. Díez D. Lithgow AM. Gómez PM. Basabe P. Garrido NM. Tetrahedron  1994,  50:  10995 
• 3b Urones JG. Díez D. Gómez PM. Marcos IS. Basabe P. Moro RF. J. Chem. Soc., Perkin Trans. 1  1997,  1815 
• 4 Marcos IS. Moro RF. Carballares S. Urones JG. Synlett  2000,  541 
• 5 Marcos IS. Moro RF. Carballares S. Urones JG. Tetrahedron Lett.  1999,  40:  2615 
• 6 Marcos IS. Moro RF. Carballares S. Urones JG. Tetrahedron  2001,  57:  713 
• 7a Haines AH. Methods for the Oxidation of Organic Compounds. Alkanes, Alkenes, Alkynes and Arenes   Academic Press; London: 1985.  p.73 
• 7b VanRheenen V. Kelly RC. Cha DY. Tetrahedron Lett.  1976,  1973 
• 7c VanRheenen V. Cha DY. Hartley WM. Org. Synth.  1979,  58:  43 
• 7d Ray R. Matteson DS. Tetrahedron Lett.  1980,  21:  449 
• 7e Schroder M. Chem. Rev.  1980,  80:  187 
• 8a Wolf FJ. Weijlard J. Org. Synthesis, Coll. Vol.4   Wiley and Sons; New York: 1963.  p.124 
• 8b Hale KJ. Hough L. Richardson AC. Tetrahedron Lett.  1987,  28:  891 
• 9 Paquette LA. Reagents for Organic Synthesis   Vol. 6:  Wiley and Sons; New York: 1995.  p.4162 
• 10a Winterfeldt E. Synthesis  1975,  617 
• 10b Yoon NM. Gyoung YS. J. Org. Chem.  1985,  50:  2443 
• 11a Collins JC. Hess WW. Frank FJ. Tetrahedron Lett.  1968,  3363 
• 11b Ratcliffe R. Rodehorst R. J. Org. Chem.  1970,  35:  4000 
• 11c Collins JC. Hess WW. Org. Synth.  1972,  52:  5 
• 11d Schwartz MA. Crowell JD. Musser JH. J. Am. Chem. Soc.  1972,  94:  4361 
• 12a Sasaki M. Murae T. Takahashi T. J. Org. Chem.  1990,  55:  528 
• 12b Govindan SV. Fuchs PL. J. Org. Chem.  1988,  53:  2593 
• 13 Paquette LA. Reagents for Organic Synthesis   Vol. 7:  Wiley and Sons; New York: 1995.  p.4593 
• 14a Chiara J. Cabri W. Hanessian S. Tetrahedron Lett.  1991,  32:  1125 
• 14b Boiron A. Zillig P. Faber D. Giese B. J. Org. Chem.  1998,  63:  5877 
• 14c Adinolfi M. Barone G. Iadonisi A. Mangoni NL. Tetrahedron Lett.  1998,  39:  2021 
• 14d Uenishi J. Masuda S. Wakabayashi S. Tetrahedron Lett.  1991,  32:  5097 
• 14e Adinolfi M. Barone G. Ladonisi A. Mangoni L. Manna R. Tetrahedron  1997,  53:  11767 
• 14f Kornienko A. Alarcao M. Tetrahedron Lett.  1997,  38:  6497 
• 14g Chiara J. Martín-Lomas M. Tetrahedron Lett.  1994,  35:  2969 
• 15 Mahn DDK. Fetizon M. Lazare S. Tetrahedron  1978,  34:  1207 
• 16a House H. Tefertiller B. Olmstead H. J. Org. Chem.  1968,  33:  935 
• 16b House H. Bare T. J. Org. Chem.  1968,  33:  943 

17

15-Hibaen-14-one(23): R_f = 0.42(Hex/EtOAc 9:1); mp 95-98 ºC; [α]_D ²⁰ -33.2 (c 0.5, CHCl₃). IR: 2953, 1759, 1177, 721 cm^-1. ¹H NMR (400 MHz, CDCl₃): δ = 6.12 and 5.89 (1 H, d ea, J = 7.0 Hz, H-15 and H-16); 1.94 (1 H, dt, J = 4.7 and 13.3 Hz, H-7); 1.05 (3 H, s, Me-17); 0.87, 0.87 and 0.83 (3 Me, s each, Me-18, Me-19 and Me-20) ppm. ¹³C NMR (100 MHz, CDCl₃): δ = 39.2 (C-1); 18.5 (C-2); 41.7 (C-3); 33.1 (C-4); 54.6 (C-5); 19.0 (C-6); 27.2 (C-7); 55.4 (C-8); 55.9 (C-9); 38.2 (C-10); 18.4 (C-11); 35.3 (C-12); 50.9 (C-13); 220.0 (C-14); 133.0 (C-15); 132.3 (C-16); 16.5 (C-17); 33.5 (C-18); 21.9 (C-19); 15.5 (C-20). Anal. Calcd for C₂₀H₃₀O: C, 83.86; H, 10.56. Found: C, 83.76; H, 10.66.