Subscribe to RSS
Please copy the URL and add it into your RSS Feed Reader.
https://www.thieme-connect.de/rss/thieme/en/10.1055-s-00000083.xml
Synlett 2015; 26(07): 927-930
DOI: 10.1055/s-0034-1380122
DOI: 10.1055/s-0034-1380122
letter
Biomimetic Total Synthesis of 6a,7,8,9,10,10a-Hexahydro-3,6,9-trimethyl-6-(4-methylpent-3-en-1-yl)-1,9-epoxy-6H-dibenzo-[b,d]pyran and Its Diastereoisomer
Further Information
Publication History
Received: 30 November 2014
Accepted after revision: 27 December 2014
Publication Date:
10 February 2015 (online)
Abstract
The first total synthesis of 6a,7,8,9,10,10a-hexahydro-3,6,9-trimethyl-6-(4-methylpent-3-en-1-yl)-1,9-epoxy-6H-dibenzo[b,d]pyran and its diastereoisomer via tandem pericyclic reactions were achieved in one step. Our biomimetic strategy features a sequential Aldol-type addition, 6π electrocyclization, and hetero-Diels–Alder cycloaddition, where three rings, two C–C bonds, and two C–O bonds were spontaneously constructed in a highly efficient way.
Key words
biomimetic - total synthesis - tandem pericyclic reactions - 6π electrocyclization - hetero-Diels–Alder cycloadditionSupporting Information
- Supporting information for this article is available online at http://dx.doi.org/10.1055/s-0034-1380122.
- Supporting Information
-
References and Notes
- 1a Classics in Total Synthesis . Nicolaou KC, Sorensen EJ. VCH; Weinheim: 1996
- 1b Beaudry CM, Trauner D. Org. Lett. 2002; 4: 2221
- 1c Moses JE, Baldwin JE, Bruckner S, Eade SJ, Adlington RM. Org. Biomol. Chem. 2003; 1: 3670
- 1d Parker KA, Lim Y.-H. J. Am. Chem. Soc. 2004; 126: 15968
- 2a Kurdyumov AV, Hsung RP, Ihlen K, Wang J. Org. Lett. 2003; 5: 3935
- 2b Paduraru MP, Wilson PD. Org. Lett. 2003; 5: 4911
- 3a Lee JC, Strobel GA, Lobkovsky E, Clardy J. J. Org. Chem. 1996; 61: 3232
- 3b Li CM, Johnson RP, Porco JA. Jr. J. Am. Chem. Soc. 2003; 125: 5095
- 5a Snider BB, Lobera M. Tetrahedron Lett. 2004; 45: 5015
- 5b Zhou J, Lobera M, Neubert-Langille BJ, Snider BB. Tetrahedron 2007; 63: 10018
- 6a Lee YR, Choi JH, Yoon SH. Tetrahedron Lett. 2005; 46: 7539
- 6b Lee YR, Wang X, Noh SK, Lyoo WS. Synth. Commun. 2006; 36: 3329
- 7 Kitanaka S, Iwata N. JP 2002265463 A, 2002
- 8 Liu L.-Y, Li Z.-H, Ding Z.-H, Dong Z.-J, Li G.-T, Li Y, Liu J.-K. J. Nat. Prod. 2013; 76: 79
- 9 See ref. 7 and the Supporting Information for the comparison of the natural products and our synthesized compounds.
- 10a Corey EJ, Gilman NW, Ganem BE. J. Am. Chem. Soc. 1968; 90: 5616
- 10b Ishihara K, Ishibashi H, Yamamoto H. J. Am. Chem. Soc. 2002; 124: 3647
- 11 Diastereoselective Total Synthesis of 3,6,9-Trimethyl-6-(4-methylpent-3-en-1-yl)-1,9-epoxy-6H-dibenzo[b,d]pyran (1) (2E,6E)-Farnesal (440 mg, 2 mmol) and 5-methylbenzene-1,3-diol (372 mg, 3 mmol) were added to pyridine (15 mL) and the mixture was refluxed rigorously at 160 °C for 16 h under argon. The reaction mixture was cooled to r.t., and the solvent was evaporated in vacuo. The residue was purified by column chromatography on silica gel with the appropriate mixture of hexane and EtOAc to give 6a,7,8,9,10,10a-hexahydro-3,6,9-trimethyl-6-(4-methylpent-3-en-1-yl)-1,9-epoxy-6H-dibenzo[b,d]pyran (1, 476 mg, 73%) as pale yellow liquid. IR (film): νmax = 1621, 1067 cm–1. 1H NMR (400 MHz, CDCl3): δ = 6.31 (s, 1 H), 6.27 (s, 1 H), 5.17 (t, J = 7.0 Hz, 1 H), 2.85 (s, 1 H), 2.25 (s, 3 H), 2.21–2.19 (m, 1 H), 2.17 (dd, J = 4.5, 3.3 Hz, 1 H), 2.08 (ddd, J = 11.6, 5.3, 2.9 Hz, 2 H), 1.95–1.85 (m, 1 H), 1.82–1.73 (m, 3 H), 1.71 (s, 3 H), 1.65 (s, 3 H), 1.46–1.38 (m, 1 H), 1.37 (s, 3 H), 0.96 (s, 3 H), 0.87 (dt, J = 6.6, 5.1 Hz, 1 H), 0.63 (ddd, J = 25.0, 13.3, 6.1 Hz, 1 H). 13C NMR (101 MHz, CDCl3): δ = 156.7, 156.5, 137.2, 131.8, 124.3, 114.3, 110.7, 109.6, 85.8, 74.5, 45.3, 42.1, 37.5, 35.3, 29.1, 27.9, 25.7, 22.9, 22.2, 21.7, 20.9, 17.7. HRMS (APCI): m/z calcd for C22H31O2: 327.2319; found: 327.2305 [M + H].
Selective representive examples, see:
Selective representative examples, see:
Selective representative examples, see:
(2E,6E)-Farnesal was oxidized from (2E,6E)-farnesol, see: