Synthesis, Table of Contents Synthesis 2013; 45(11): 1541-1545DOI: 10.1055/s-0033-1338429 paper © Georg Thieme Verlag Stuttgart · New YorkSynthesis of cis- and trans-Davanoids: Artemone, Hydroxydavanone, Isodavanone, and Nordavanone Authors Author Affiliations Kanny K. Wan Department of Chemistry, Harvey Mudd College, 301 Platt Boulevard, Claremont, CA 91711, USA Fax: +1(909)6077577 Email: vosburg@hmc.edu Corwyn D. Evans-Klock Department of Chemistry, Harvey Mudd College, 301 Platt Boulevard, Claremont, CA 91711, USA Fax: +1(909)6077577 Email: vosburg@hmc.edu Brian C. Fielder Department of Chemistry, Harvey Mudd College, 301 Platt Boulevard, Claremont, CA 91711, USA Fax: +1(909)6077577 Email: vosburg@hmc.edu David A. Vosburg* Department of Chemistry, Harvey Mudd College, 301 Platt Boulevard, Claremont, CA 91711, USA Fax: +1(909)6077577 Email: vosburg@hmc.edu Recommend Article Abstract Buy Article(opens in new window) All articles of this category(opens in new window) This paper is dedicated to Prof. Christopher T. Walsh on the occasion of his retirement in 2013. Abstract A concise and versatile synthesis of both cis and trans diastereomers of the natural products artemone, hydroxydavanone, isodavanone, and nordavanone has been accomplished. The preparation of trans-davanone is also described. Each synthesis is six to eight steps from geranyl acetate, with differentiation between cis and trans products occurring through a diastereoselective cyclization prior to derivatization. Many of these compounds are minor components of davana oil and have now been synthesized for the first time. Key words Key wordsdavanone - terpenoids - total synthesis - stereoselective synthesis - green chemistry - asymmetric allylic O-alkylation Full Text References References 1 Misra LN, Chandra A, Thakur RS. Phytochemistry 1991; 30: 549 2 Sipma G, van der Waal B. Rec. Trav. Chim. Pays-Bas 1968; 87: 715 3 Vajs V, Trifunovic S, Janackovic P, Sokovic M, Milosavljevic S, Tesevic V. J. Serb. Chem. Soc. 2004; 69: 969 4 Perfumi M, Paparelli F, Cingolani ML. J. Essent. Oil Res. 1995; 7: 387 5 Schmidt E, Bail S, Friedl SM, Jirovetz L, Buchbauer G, Wanner J, Denkova Z, Slavchev A, Stoyanova A, Geissler M. Nat. Prod. Commun. 2010; 5: 1365 6a Naegeli P, Weber G. Tetrahedron Lett. 1970; 959 6b Ohloff G, Giersch W. Helv. Chim. Acta 1970; 53: 841 6c Birch AJ, Corrie JE. T, Subba Rao GS. R. Aust. J. Chem. 1970; 23: 1811 6d Bartlett PA, Holmes CP. Tetrahedron Lett. 1983; 24: 1365 6e Honda Y, Ori A, Tsuchihashi G. Chem. Lett. 1987; 1259 6f Molander GA, Haas J. Tetrahedron 1999; 55: 617 6g Morrison KC, Litz JP, Scherpelz KP, Dossa PD, Vosburg DA. Org. Lett. 2009; 11: 2217 6h Sabitha G, Prasad MN, Bhikshapathi M, Yadav JS. Synthesis 2010; 807 7a Baran PS, Shenvi RA, Mitsos CA. Angew. Chem. Int. Ed. 2005; 44: 3714 In our case and in Baran’s, neighboring Lewis basic groups may stabilize the tetrahedral intermediate and prevent a second Grignard addition. Double prenylation (likely γ and then α) of esters has been observed for simpler esters: 7b Inaba T, Aoki H, Watanabe S, Sakamoto M, Fujita T. J. Chem. Tech. Biotechnol. 1991; 52: 407 . It is possible that α-prenylation is preferred for steric reasons on congested carbonyls, as in Inaba’s presumed γ-prenyl ketone intermediates and our Weinreb amide 6. Molander also observed α-prenylation of a Weinreb amide with a Grignard reagent; see ref. 6f 8 Naegeli P, Klimes J, Weber G. Tetrahedron Lett. 1970; 5021 9 Thomas AF, Ozainne M. Helv. Chim. Acta 1974; 57: 2062 10 For nonstereoselective syntheses of all davanone stereoisomers, see references 6a–c. 11 Patterson I, Yeung K.-S, Smaill JB. Synlett 1993; 774 12 Denmark SE, Stavenger RA. J. Am. Chem. Soc. 2000; 122: 8837 13 Shorter reaction times left the silyl protecting group intact. 14 All compounds have an 8:1 er derived from an initial Sharpless asymmetric epoxidation; see ref. 6g. 15a Richter JM, Ishihara Y, Masuda T, Whitefield BW, Llamas T, Pohjakallio A, Baran PS. J. Am. Chem. Soc. 2008; 130: 17938 15b Burns NZ, Baran PS, Hoffmann RW. Angew. Chem. Int. Ed. 2009; 48: 2854 16 Wan, K. K.; Maloney, K. N., unpublished results. 17 Bidan G, Kossanyi J, Meyer V, Morizur J.-P. Tetrahedron 1977; 2193 Supplementary Material Supplementary Material Supporting Information (PDF)
