Synlett 2004(12): 2233-2235  
DOI: 10.1055/s-2004-830889
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Brief Total Synthesis of Eupolauramine

Véronique Rys, Axel Couture*, Eric Deniau, Stéphane Lebrun, Pierre Grandclaudon
Laboratoire de Chimie Organique Physique, UMR 8009 ‘Laboratoire de Chimie Organique et Macromoléculaire’, Université des Sciences et Technologies de Lille, Bâtiment C3(2), 59655 Villeneuve d’Ascq Cédex, France
Fax: +33(3)20336119; e-Mail: axel.couture@univ-lille1.fr;
Further Information

Publication History

Received 14 May 2004
Publication Date:
04 August 2004 (online)

Abstract

A concise synthesis of the alkaloid eupolauramine has been achieved. The key step was a benzotriazolyl-mediated connection of a bromoaryl unit to the azaisoindolinone framework by an enol ether function. Free radical cyclization then provided the natural product.

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All new compounds have been fully characterized. 1H NMR (300 MHz, CDCl3), 13C NMR and APT spectral data (75 MHz, CDCl3) and elemental analysis of the key intermediates for Compound 10: white solid, mp 176-177 °C. 1H NMR: δ = 1.12 (s, 9 H, 3 CH3), 2.83 (s, 3 H, NCH3), 5.89 (d, J = 8.3 Hz, 1 H, ArH), 6.15 (d, J = 7.8 Hz, 1 H, ArH), 6.81 (t, J = 7.8 Hz, 1 H, ArH), 7.06 (t, J = 6.8 Hz, 1 H, ArH), 7.17 (t, J = 7.8 Hz, 1 H, ArH), 7.24-7.36 (m, 2 H, ArH + CHOC=O), 7.55 (d, J = 8.3 Hz, 1 H, ArH), 7.76 (d, J = 4.8 Hz, 1 H, ArH), 8.11-8.14 (m, 1 H, ArH), 9.05 (d, J = 4.8 Hz, 1 H, ArH), 9.17 (s, 1 H, ArH). 13C NMR: δ = 27.0 (3 CH3), 27.9 (CH3), 38.6 (C), 74.4 (CH), 83.4 (C), 109.9 (CH), 117.7 (CH), 122.0 (CH), 124.8 (CH), 125.6 (C), 126.8 (CH), 128.6 (CH), 128.7 (CH), 130.8 (CH), 131.4 (C), 132.5 (C), 133.8 (CH), 135.6 (C), 140.7 (C), 145.6 (CH), 146.6 (C), 151.1 (CH), 165.1 (C), 175.7 (C). Anal. Calcd for C26H24BrN5O3 (534.42): C, 58.44; H 4.53; N, 13.10. Found: C, 58.79; H, 4.84; N, 13.37. Compound Z-3: white solid, mp 169-170 °C. 1H NMR: δ = 1.25 (s, 9 H, 3 CH3), 3.55 (s, 3 H, NCH3), 7.25-7.47 (m, 3 H, ArH), 7.64-7.76 (m, 3 H, ArH), 8.64 (d, J = 4.9 Hz, 1 H, ArH). 13C NMR: δ = 26.8 (3 CH3), 29.4 (CH3), 39.3 (C), 116.8 (CH), 124.5 (C), 127.4 (C), 127.9 (CH), 130.0 (C), 131.8 (C), 132.0 (CH), 133.7 (CH), 134.3 (C), 134.4 (CH), 135.8 (C), 143.9 (CH), 149.3 (CH), 165.4 (C), 176.4 (C). Anal. Calcd for C20H19BrN2O3 (415.29): C, 57.84; H, 4.61; N, 6.75. Found: C, 57.61; H, 4.54; N, 6.47.