Synlett 2006(14): 2211-2214  
DOI: 10.1055/s-2006-950398
LETTER
© Georg Thieme Verlag Stuttgart · New York

Sequential Double Claisen Rearrangement and Two-Directional Ring-Closing Metathesis as a Route to Various Benzofused Bisoxepin and Bisoxocin Derivatives

Shital K. Chattopadhyay*, Titas Biswas, Susama Maity
Department of Chemistry, University of Kalyani, Kalyani - 741235, India
Fax: skchatto@yahoo.com; e-Mail: +91(33)25828282;
Further Information

Publication History

Received 14 February 2006
Publication Date:
24 August 2006 (online)

Abstract

A synthetic strategy based on tandem application of double Claisen rearrangement and two-directional ring-closing metathesis reaction as key-steps has been developed for the synthesis of various hitherto unknown tri-, tetra- and pentacyclic benzofused bisoxepin and bisoxocin derivatives.

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General Procedure for the Synthesis of the Bisdienes.
A heterogeneous mixture of the appropriate biphenol (1.0 mmol), allyl bromide (or 4-bromobutene; 4.0 mmol), anhyd K2CO3 (8.0 mmol) and dry acetone (10 mL) was refluxed under stirring under nitrogen atmosphere for 18 h. It was then filtered and the filter cake was washed with acetone (2 × 10 mL). The combined acetone solution was then concentrated in vacuo and the residual mass was chromatographed over silica gel.
Data for compound 3: 1H NMR (300 MHz, CDCl3): δ = 6.84 (s, 1 H), 6.13-5.91 (m, 4 H), 5.45 (dd, 2 H, J = 17.1, 1.2 Hz), 5.27 (d, 2 H, J = 9.4 Hz), 5.08 (overlapping doublets, 4 H), 4.28 (d, 4 H, J = 5.4 Hz), 3.36 (d, 4 H, J = 6.5 Hz), 2.22 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 153.9 (s), 137.2 (d), 129.4 (d), 128.7 (d), 125.0 (s), 115.8 (t), 111.4 (s), 75.1 (t), 34.1 (t), 10.7 (q). Anal. Calcd for C19H24O2: C, 80.24; H, 8.51. Found: C, 80.48; H, 8.39.
Compound 10: 1H NMR (300 MHz, CDCl3): δ = 6.67 (s, 2 H), 6.04-5.96 (m, 4 H), 5.42 (dd, 2 H, J = 17.2, 1.4 Hz), 5.22 (dd, 2 H, J = 10.4, 1.1 Hz), 5.04-5.01 (m, 4 H), 4.48 (d, 4 H, J = 1.2 Hz), 3.37 (d, 4 H, J = 6.3 Hz). 13C NMR (75 MHz, CDCl3): δ = 150.3 (s), 137.1 (d), 133.8 (d), 127.5 (s), 116.8 (t), 115.4 (t), 114.5 (d), 69.8 (t), 34.2 (t). Anal. Calcd for C18H22O2: C, 79.96; H, 8.20. Found: C, 80.07; H, 8.23.
Compound 16: mp 82 °C. 1H NMR (300 MHz, CDCl3): δ = 7.40-7.34 (m, 4 H), 6.88 (d, 2 H, J = 9.1 Hz), 6.15-5.98 (m, 4 H), 5.45 (d, 2 H, J = 17.4 Hz), 5.29 (d, 2 H, J = 9.6 Hz), 5.14-5.05 (m, 4 H), 4.58 (d, 4 H, J = 4.8 Hz), 3.48 (d, 4 H, J = 6.5 Hz). 13C NMR (75 MHz, CDCl3): δ = 155.3 (s), 136.9 (d), 133.5 (d), 133.4 (d), 129.0 (s), 128.3 (s), 125.3 (d), 116.8 (t), 115.4 (t), 111.8 (d), 68.8 (t), 34.5 (t).
Compound 28: 1H NMR (300 MHz, CDCl3): δ = 7.82 (d, 2 H, J = 8.4 Hz), 7.32 (d, 2 H, J = 8.5 Hz), 6.26-6.15 (m, 2 H), 6.08-5.99 (m, 2 H), 5.51 (dd, 2 H, J = 17.4, 1.4 Hz), 5.32 (dd, 2 H, J = 11.2, 1.0 Hz), 5.13-5.07 (m, 4 H), 4.49 (d, 4 H, J = 5.4 Hz), 3.59 (d, 4 H, J = 6.3 Hz). 13C NMR (75 MHz, CDCl3): δ = 152.5 (s), 137.2 (d), 133.9 (d), 128.9 (s), 128.3 (d), 128.0 (s), 118.3 (d), 117.3 (t), 115.9 (t), 75.3 (t), 33.9 (t). Anal. Calcd for C22H24O2: C, 82.46; H, 7.55. Found: C, 82.57; H, 7.64.
Compound 34: mp 98 °C. IR (KBr,): 1669, 1258, 1073, 993 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.04 (d, 2 H, J = 7.9 Hz), 7.60 (d, 2 H, J = 7.9 Hz), 6.27-6.16 (m, 2 H), 6.02-5.94 (m, 2 H), 5.44 (dd, 2 H, J = 17.2, 1.0 Hz), 5.32 (d, 2 H, J = 10.1 Hz), 5.16-5.09 (m, 4 H), 4.54 (d, 4 H, J = 5.6 Hz), 3.55 (d, 4 H, J = 6.4 Hz). 13C NMR (75 MHz, CDCl3): δ = 180.5 (s), 156.7 (s), 141.6 (s), 135.7 (d), 135.5 (s), 133.7 (d), 125.3 (s), 123.4 (d), 118.0 (t), 117.0 (t), 75.2 (t), 34.2 (t). Anal. Calcd for C26H24O4: C, 77.98; H, 6.04. Found: C, 78.11; H, 6.20.

20

General Procedure for TDRCM.
To a solution of the appropriate bisdiene (0.2 mmol) in dry, degassed CH2Cl2 (25 mL) was added Grubbs’ catalyst (5, 15 mg, 10 mol%) under argon atmosphere and the resulting solution was stirred at r.t. for the time indicated in Table [1] . The solvent was the removed in vacuo and the residue was chromatographed over silica gel.

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All new compounds reported here gave satisfactory spectroscopic and/or analytical data.
Compound 6: mp 140-141 °C. 1H NMR (300 MHz, CDCl3): δ = 6.65 (s, 1 H), 5.85-5.79 (m, 2 H), 5.43 (d, 2 H, J = 11.5 Hz), 4.53 (s, 4 H), 3.37 (d, 4 H, J = 2.5 Hz), 2.20 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 155.5 (s), 131.5 (s), 127.3 (d), 126.0(d), 125.1 (d), 123.4 (s), 70.0(t), 31.3 (t), 8.9 (q). Anal. Calcd for C15H16O2: C, 78.92; H, 7.06. Found: C, 79.18; H, 7.21. MS (EI): m/z = 228 [M+].
Compound 7: 1H NMR (300 MHz, CDCl3): δ = 6.77 (s, 1 H), 5.91-5.84 (m, 2 H), 5.68-5.62 (m, 2 H), 3.95 (t, 4 H, J = 4.7 Hz), 3.32 (d, 4 H, J = 7.0 Hz), 2.44-2.39 (m, 4 H), 2.15 (s, 3 H). 13C NMR (75 MHz, CDCl3): δ = 154.7 (s), 134.0 (d), 133.1 (s), 126.9 (d), 125.9 (d), 125.4 (s), 71.9 (t), 31.4 (t), 28.8 (t), 9.6 (q). Anal. Calcd for C17H20O2: C, 79.65; H, 7.86. Found: C, 79.78; H, 8.01.
Compound 12: mp 143 °C. 1H NMR (300 MHz, CDCl3): δ = 6.79 (s, 2 H), 5.85-5.79 (m, 2 H), 5.45 (td, 2 H, J = 11.4, 1.4 Hz), 4.54 (d, 4 H, J = 2.2 Hz), 3.41 (s, 4 H). 13C NMR (75 MHz, CDCl3): δ = 154.5 (s), 135.0 (s), 127.4 (d), 125.6 (d), 121.6 (d), 71.2 (t), 31.3 (t). MS (EI): m/z = 214 (100).
Compound 13: 1H NMR (300 MHz, CDCl3): δ = 6.80 (s, 2 H), 5.98-5.87 (m, 2 H), 5.18-5.01 (m, 2 H), 3.95 (t, 4 H, J = 6.5 Hz), 3.35-3.26 (m, 4 H), 2.54-2.51 (m, 4 H). Anal. Calcd for C16H18O2: C, 79.31; H, 7.49. Found: C, 79.39; H, 7.52.
Compound 18: mp 104 °C. 1H NMR (300 MHz, CDCl3): δ = 7.34 (dd, 2 H, J = 8.2, 2.3 Hz), 7.25 (d, 2 H, J = 2.8 Hz), 7.10 (d, 2 H, J = 8.1 Hz), 5.93-5.84 (m, 2 H), 5.52-5.47 (m, 2 H), 4.62-4.60 (m, 4 H), 3.53 (d, 4 H, J = 2.8). 13C NMR (75 MHz, CDCl3): δ = 158.0 (s), 136.7 (s), 136.2 (s), 127.5 (d), 127.3 (d), 126.3 (d), 125.7 (d), 121.7 (d), 71.2 (t), 31.9 (t). MS (EI): m/z = 290 [M+]. Anal. Calcd for C20H18O2: C, 82.73; H, 6.25. Found: C, 82.91; H, 6.44.
Compound 19: mp 80 °C. 1H NMR (300 MHz, CDCl3): δ = 7.37-7.34 (m, 4 H), 7.05 (d, 2 H, J = 8.4 Hz), 5.94 (td, 2 H, J = 10.9, 6.6 Hz), 5.69-5.60 (m, 2 H), 4.08 (t, 4 H, J = 4.9 Hz), 3.46 (d, 4 H, J = 6.5 Hz), 2.41-2.36 (m, 4 H). 13C NMR (75 MHz, CDCl3): δ = 156.7 (s), 136.2 (s), 135.8 (s), 127.1 (d), 126.9 (d), 125.8 (d), 124.3 (d), 122.0 (d), 72.1 (t), 32.1 (t), 28.4 (t). Anal. Calcd for C22H22O2: C, 82.99; H, 6.96. Found: C, 82.91; H, 6.64.
Compound 24: 1H NMR (300 MHz, CDCl3): δ = 7.19-7.05 (m, 6 H), 5.87-5.80 (m, 2 H), 5.39 (d, 2 H, J = 11.4 Hz), 4.36 (t, 4 H, J = 2.1 Hz), 3.54 (d, 4 H, J = 2.4 Hz). 13C NMR (75 MHz, CDCl3): δ = 155.8 (s), 136.6 (s), 132.0 (s), 129.3 (d), 128.1 (d), 127.5 (d), 125.3 (d), 123.4 (d), 70.4 (t), 31.8 (t). MS (EI): m/z = 290 [M+]. Anal. Calcd for C20H18O2: C, 82.73; H, 6.25. Found: C, 82.84; H, 6.32.
Compound 25: 1H NMR (300 MHz, CDCl3): δ = 7.17-7.14 (m, 4 H), 7.05 (d, 2 H, J = 7.4 Hz), 5.94 (td, 2 H, J = 10.9, 6.9 Hz), 5.59 (td, 2 H, J = 10.8, 7.3 Hz), 3.63 (t, 4 H, J = 4.9 Hz), 3.47 (d, 4 H, J = 6.7 Hz), 2.30-2.25 (m, 4 H). HRMS (TOF MS ES+): m/z calcd.: 318.1619; found: 318.1628.
Compound 30: 1H NMR (300 MHz, CDCl3): δ = 7.85 (d, 2 H, J = 6.3 Hz), 7.23 (d, 2 H, J = 6.4 Hz), 5.93-5.89 (m, 2 H), 5.54 (dquint, 2 H, J = 8.7, 1.0 Hz), 4.70-4.68 (m, 4 H), 3.64-3.62 (m, 4 H). 13C NMR (75 MHz, CDCl3): δ = 153.7 (s), 130.8 (s), 128.4 (s), 127.5 (d), 125.7 (d), 117.0 (d), 70.1 (t), 32.0(t). MS (EI): m/z = 264 [M+].
Compound 31: mp 176-178 °C. 1H NMR (300 MHz, CDCl3): δ = 7.78 (d, 2 H, J = 8.4 Hz), 7.33 (d, 2 H, J = 9.1 Hz), 6.02 (dt, 2 H, J = 10.7, 7.1 Hz), 5.63 (dt, 2 H, J = 10.7, 7.3 Hz), 4.18 (t, 4 H, J = 4.7 Hz), 3.54 (d, 4 H, J = 7.1 Hz), 2.51-2.46 (m, 4 H). 13C NMR (75 MHz, CDCl3): δ = 152.4 (s), 133.6 (d), 132.6 (s), 129.3 (s), 127.6 (d), 127.3 (d), 117.7 (d), 72.6 (t), 31.7 (t), 29.0 (t). Anal. Calcd for C20H20O2: C, 82.16; H, 6.89. Found: C, 82.33; H, 7.02. MS (EI): m/z = 292 [M+].
Compound 35: mp 248-251 °C. 1H NMR (300 MHz, CDCl3): δ = 7.97 (d, 2 H, J = 7.9 Hz), 7.48 (d, 2 H, J = 7.8 Hz), 5.88-5.85 (m, 2 H), 5.53 (d, 2 H, J = 11.0 Hz), 4.83 (s, 4 H), 3.58 (s, 4 H). 13C NMR (75 MHz, CDCl3): δ = 183.0 (s), 158.2 (s), 146.4 (s), 135.6 (s), 133.8 (d), 128.3 (d), 126.3 (s), 124.7 (d), 123.9 (d), 71.1 (t), 31.1 (t). Anal. Calcd for C22H16O4: C, 76.73; H, 4.68. Found: C, 76.94; H, 4.62. MS (TOF MS ES+): m/z = 344 [M+].