Synlett 2006(20): 3479-3483  
DOI: 10.1055/s-2006-956481
LETTER
© Georg Thieme Verlag Stuttgart · New York

Hetero-Diels-Alder Reaction of 3-Bromo-7-(bromomethyl)tetracyclo[5.3.1.02,6.04,8]undec-10(12)-ene-9,11-dione with Pentafulvenes: Facile Synthesis of Novel Polycyclic Cage Compounds Having a Pyran Ring

Beena Jamesa, E. Sureshb, Mangalam S. Nair*a
a Organic Chemistry Section, Regional Research Laboratory (CSIR), Trivandrum 695019, India
Fax: +91(471)2491712; e-Mail: msn555in@yahoo.co.in;
b Analytical Science Discipline, Central Salt and Marine Chemicals Research Institute (CSIR), Bhavnagar 364002, India
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Publikationsverlauf

Received 24 June 2006
Publikationsdatum:
08. Dezember 2006 (online)

Abstract

The enone moiety of 3-bromo-7-(bromomethyl)tetracyclo[5.3.1.02,6.04,8]undec-10(12)-ene-9,11-dione undergoes facile hetero-Diels-Alder reaction with pentafulvenes leading to novel cage systems with pyran moiety

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Crystal Data for Compound 6a: C27H24Br2O2, colorless plates, 0.20 × 0.10 × 0.05 mm3; formula weight = 540.28; monoclinic, space group: P21/c; unit cell dimensions: a = 12.4363(16) Å, b = 14.1854(18) Å, c = 12.8075(16) Å, β = 91.000(2)°; V = 2259.1 (5) Å3; Z = 4; D(calcd) = 1.589 Mg/m3; F(000) = 1088; absorption coefficient = 3.610 mm-1; GoF = 0.992; R indices(I >2σ): R1 = 0.0565, wR2 = 0.1345. Crystal structure data for 6a have been deposited at the Cambridge Crystallographic Data Centre and the allocated deposition number is CCDC 602750.

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Spectroscopic Data for Selected Compounds. Data for 6a: crystallized from CH2Cl2-hexane (1:5) mixture; mp 135-137 °C. Yield: 65%. FT-IR (KBr): 2974, 1751, 1665, 1243, 1228, 1176, 1070, 893, 692 cm-1. 1H NMR (300 MHz, CDCl3): δ = 7.22-7.46 (m, 5 H), 6.83-6.93 (m, 1 H), 6.57 (d, J = 15.3 Hz, 1 H), 6.26 (d, J = 5.7 Hz, 1 H), 6.15 (d, J = 11.4 Hz, 1 H), 6.02 (d, J = 5.4 Hz, 1 H), 5.29 (d, J = 5.7 Hz, 1 H), 4.29 (s, 1 H), 3.61 (d, J = 10.2 Hz, 1 H), 3.37-3.44 (q, J = 15.3 Hz, 1 H), 3.29 (d, J = 10.2 Hz, 1 H), 2.99-3.04 (t, J 1 = 6.3 Hz, J 2 = 7.5 Hz, 1 H), 2.84 (d, J = 4.5 Hz, 1 H), 2.63-2.74 (m, 3 H), 2.38-2.49 (m, 2 H), 2.02-2.10 (m, 1 H), 1.85 (d, J = 11.1 Hz, 1 H). 13C NMR (75 MHz, CDCl3): δ = 203.2, 149.8, 148.8, 137.5, 135.5, 132.7, 129.7, 128.9, 128.7, 127.6, 126.3, 125.2, 121.5, 103.5, 81.8, 55.5, 55.4, 54.1, 49.9, 45.8, 45.6, 45.0, 36.7, 35.4, 31.6, 28.2, 22.6. HRMS (EI): m/z [M+] calcd for C27H24O2Br2: 538.0143; found: 538.0132.
Data for 6b: crystallized from CH2Cl2-hexane (1:5) mixture; mp 124-126 °C. Yield: 61%. FT-IR (KBr): 2969, 1746, 1670, 1233, 1008, 974, 677, 653 cm-1. 1H NMR (300 MHz, CDCl3): δ = 7.46 (s, 1 H), 6.43 (s, 1 H), 6.25-6.27 (t, J 1 = 3.3 Hz, J 2 = 2.4 Hz, 2 H), 6.12 (s, 1 H), 5.99 (d, J = 3.6 Hz, 1 H), 5.30 (d, J = 6.9 Hz, 1 H), 4.29 (s, 1 H), 3.67-3.74 (dd, J = 6.9 Hz, 1 H), 3.62 (d, J = 10.2 Hz, 1 H), 3.27 (d, J = 10.2 Hz, 1 H), 2.98-3.02 (t, J 1 = 6.6 Hz, J 2 = 6.0 Hz, 1 H), 2.82 (d, J = 4.5 Hz, 1 H), 2.61-2.70 (m, 3 H), 2.56 (d, J = 8.4 Hz, 1 H), 2.34 (d, J = 4.5 Hz, 1 H), 1.93-2.01 (dd, J 1 = J 2 = 6.6 Hz, 1 H), 1.84 (d, J = 11.4 Hz, 1 H). 13C NMR (75 MHz, CDCl3): δ = 203.2, 152.6, 148.3, 146.9, 142.1, 137.2, 135.9, 111.6, 109.5, 109.1, 82.3, 55.6, 53.9, 49.9, 45.9, 45.6, 45.0, 37.9, 35.4, 31.6, 27.4, 22.6, 14.I. HRMS: m/z [M+] calcd for C23H20O3Br2: 501.9779; found: 501.9768.
Data for 6f: crystallized from CH2Cl2-hexane (1:5) mixture; mp 146-148 °C. Yield: 64%. FT-IR (KBr): 3434, 1756, 1665, 1226, 1243, 869, 658 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.62 (d, J = 4.5 Hz, 1 H), 7.63-7.58 (t, J 1 = 6.0 Hz, J 2 = 7.5 Hz, 1 H), 7.15 (d, J = 7.8 Hz, 1 H) 7.05-7.09 (t, J 1 = 4.8 Hz, J 2 = 7.2 Hz, 1 H), 6.30-6.35 (m, 2 H), 6.15 (d, J = 5.4 Hz, 1 H), 5.30 (d, J = 6.3 Hz, 1 H), 4.32 (s, 1 H), 4.20-4.28 (m, 1 H), 3.62 (d, J = 10.5 Hz, 1 H), 3.28 (d, J = 10.2 Hz, 1 H), 2.97-3.01 (t, J 1 = 7.2 Hz, J 2 = 6.3 Hz, 1 H), 2.82 (d, J = 4.5 Hz, 1 H), 2.61-2.76 (m, 4 H), 2.34 (d, J = 5.1 Hz, 1 H), 1.82-1.93 (m, 2 H). 13C NMR (75 MHz, CDCl3): δ = 203.3, 156.0, 153.7, 149.4, 148.0, 139.3, 136.6, 136.1, 124.3, 120.5, 120.1, 104.5, 82.4, 55.7, 55.4, 53.9, 49.9, 46.3, 45.9, 45.0, 37.9, 35.4, 31.6, 27.8. HRMS: m/z [M+] calcd for C24H21NO2Br2: 512.9939; found: 512.9943.
Data for 6g: crystallized from CH2Cl2-hexane (1:5) mixture; mp 154-156 °C. Yield: 54%. FT-IR (KBr): 2983, 1737, 1670, 1636, 1230, 740, 668 cm-1. 1H NMR (300 MHz, CDCl3): δ = 8.21 (s, 1 H), 7.63 (s, 1 H), 7.38 (d, J = 8.4 Hz, 1 H) 7.21-7.26 (m, 2 H), 6.57 (s, 1 H), 6.48 (s, 1 H), 6.34 (d, J = 5.7 Hz, 1 H), 5.95 (d, J = 5.4 Hz, 1 H), 5.34 (d, J = 6.9 Hz, 1 H), 4.23 (s, 1 H), 3.72-3.79 (m, 1 H), 3.61 (d, J = 10.2 Hz, 1 H), 3.27 (d, J = 10.2 Hz, 1 H), 2.92-2.96 (d, J 1 = 6.9 Hz, J 2 = 6.6 Hz, 1 H), 2.79 (d, J = 4.5 Hz, 1 H), 2.59-2.65 (m, 3 H), 2.42-2.51 (m, 1 H), 2.33 (s, 1 H), 1.99-2.01 (m, 1 H), 1.82 (d, J = 11.4 Hz, 1 H). 13C NMR (75 MHz, CDCl3): δ = 207.4, 148.5, 146.5, 138.3, 137.1, 134.3, 133.9, 124.6, 123.3, 123.0, 122.2, 120.5, 111.1, 104.9, 102.9, 82.9, 55.6, 53.9, 49.9, 45.9, 45.6, 44.9, 37.3, 35.4, 29.7, 26.5, 24.7. HRMS: m/z [M+] calcd for C27H23NO2Br2: 551.0096; found: 551.0087.