Synlett 2012; 23(20): 2919-2922
DOI: 10.1055/s-0032-1317528
letter
© Georg Thieme Verlag Stuttgart · New York

Synthetic Studies towards Stachybotrin C

Naresh Tumma
a   Division of Natural Product Chemistry, Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500607, India
b   Université de Rennes 1, UMR 6226, Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, 35043 Rennes Cedex, France   Fax: +33(2)23234425   Email: pierre.van-de-weghe@univ-rennes1.fr
,
Maiwenn Jacolot
b   Université de Rennes 1, UMR 6226, Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, 35043 Rennes Cedex, France   Fax: +33(2)23234425   Email: pierre.van-de-weghe@univ-rennes1.fr
,
Mickael Jean
b   Université de Rennes 1, UMR 6226, Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, 35043 Rennes Cedex, France   Fax: +33(2)23234425   Email: pierre.van-de-weghe@univ-rennes1.fr
,
Srivari Chandrasekhar*
a   Division of Natural Product Chemistry, Indian Institute of Chemical Technology, Uppal Road, Tarnaka, Hyderabad 500607, India
,
Pierre van de Weghe*
b   Université de Rennes 1, UMR 6226, Institut des Sciences Chimiques de Rennes, Equipe PNSCM, UFR des Sciences Biologiques et Pharmaceutiques, 2 avenue du Prof Léon Bernard, 35043 Rennes Cedex, France   Fax: +33(2)23234425   Email: pierre.van-de-weghe@univ-rennes1.fr
› Author Affiliations
Further Information

Publication History

Received: 13 September 2012

Accepted after revision: 12 October 2012

Publication Date:
09 November 2012 (online)


Abstract

The preparation of racemic des-hydroxy stachybotrin C is described. Different approaches have been studied. Observations made in the course of the synthesis show the efficiency of the intermolecular cyclization between the diethyl acetal 19 and phenol 12 leading to the benzopyran moiety 17.

Supporting Information

 
  • References and Notes

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    • 1b Nozawa Y, Ito M, Sugawara K, Hanada K, Mizoue K. J. Antibiot. 1997; 50: 641
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    • 2b Joyner PM, Cichewicz RH. Nat. Prod. Rep. 2011; 28: 26
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  • 3 Xu X, de Guzman FS, Gloer JB. J. Org. Chem. 1992; 57: 6700
  • 4 Inoue S, Kim R, Hoshino Y, Honda K. Chem. Commun. 2006; 1974
    • 5a Menon RS, Findlay AD, Bissember AC, Banwell MG. J. Org. Chem. 2009; 74: 8901
    • 5b Jean M, van de Weghe P. Tetrahedron Lett. 2011; 52: 3509
  • 6 Katoh T, Ohmori O, Iwasaki K, Inoue M. Tetrahedron 2002; 58: 1289 ; and references cited therein.
  • 7 For the preparation of 11 and 13, see the Supporting Information.
  • 8 For a significant and recent review on gold-catalyzed additions to C–C multiple bonds, see: Huang H, Zhou Y, Liu H. Beilstein J. Org. Chem. 2011; 7: 897
  • 9 The gold-catalyzed biscyclopropanation of dienynes has been already reported, see: Nieto-Oberhuber C, López S, Paz Muñoz M, Jiménez-Núñez E, Buñuel E, Cárdenas DJ, Echavarren AM. Chem.–Eur. J. 2006; 12: 1694
  • 10 North JT, Kronenthal DR, Pullockaran AJ, Real SD, Chen HY. J. Org. Chem. 1995; 60: 3397
  • 11 To a solution of 12 (500 mg, 1.34 mmol, 1.0 equiv) in anhydrous o-xylene (8 mL), 19 (790 mg, 2.68 mmol, 2.0 equiv) and 3-picoline (33 μL, 0.34 mmol, 0.25 equiv) were added. The reaction mixture was heated to reflux for 48 h, then the solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel (CH2Cl2–EtOAc, 9:1→4:1) to afford 17 (775 mg, 75%) as a brown oil. 1H NMR (500 MHz, CDCl3): δ = 1.40 (s, 3 H), 1.56 (s, 3 H), 1.59 (s, 3 H), 1.66–1.76 (m, 5 H), 1.92–1.97 (m, 2 H), 2.01–2.15 (m, 4 H), 2.92 (t, J = 7.5 Hz, 2 H), 3.47 (s, 3 H), 3.48 (s, 3 H), 3.74–3.84 (m, 2 H), 4.16 (s, 2 H), 5.05–5.14 (m, 2 H), 5.15 (s, 2 H), 5.22 (s, 2 H), 5.61 (d, J = 10.2 Hz, 1 H), 6.76 (d, J = 10.2 Hz, 1 H), 6.96 (d, J = 8.7 Hz, 2 H), 7.07 (s, 1 H), 7.16 (d, J = 8.7 Hz, 2 H). 13C NMR (125 MHz, CDCl3): δ = 15.9, 17.7, 22.5, 25.7, 26.6, 34.0, 39.6, 41.2, 44.3, 47.7, 55.9, 56.3, 78.9, 94.5, 95.0, 101.2, 113.6, 116.4, 117.5, 121.4, 123.6, 124.2, 129.4, 129.7, 131.4, 132.1, 133.9, 135.5, 148.2, 153.2, 155.9, 168.3. HRMS (ESI): m/z [M + Na]+ calcd for C35H45NO6Na: 598.3139; found: 598.3139.
  • 12 To a solution of 17 (200 mg, 0.35 mmol, 1.0 equiv) in anhydrous MeOH (4 mL) was added at 0 °C, acetyl chloride (100 μL, 1.39 mmol, 4.0 equiv). The solution was stirred at room temperature for 20 h then concentrated under reduced pressure and the residue was purified by column chromatography on silica gel (PE–EtOAc, 1:1) to afford 20 (140 mg, 82%) as a pale-yellow oil. 1H NMR (500 MHz, CDCl3): δ = 1.37 (s, 3 H), 1.56 (s, 3 H), 1.58 (s, 3 H), 1.66 (s, 3 H), 1.66–1.76 (m, 2 H), 1.92–1.97 (m, 2 H), 2.01–2.15 (m, 4 H), 2.85 (t, J = 7.5 Hz, 2 H), 3.70–3.84 (m, 2 H), 4.17 (s, 2 H), 5.05–5.14 (m, 2 H), 5.55 (d, J = 10.2 Hz, 1 H), 6.76–6.79 (m, 3 H), 6.96–7.01 (m, 3 H), 7.46 (br s, 1 H), 8.40 (br s, 1 H). 13C NMR (125 MHz, CDCl3): δ = 15.9, 17.7, 22.5, 25.7, 26.6, 26.6, 33.8, 39.6, 41.2, 44.4, 47.9, 79.0, 102.4, 112.2, 115.6, 117.5, 119.6, 123.7, 124.2, 129.0, 129.7, 130.2, 131.4, 133.2, 135.6, 148.4, 152.7, 154.6, 169.0. HRMS (ESI): m/z [M + Na]+ calcd for C31H37NO4Na: 510.2620; found: 510.2621.