Synlett 2007(3): 0403-0406  
DOI: 10.1055/s-2007-968030
LETTER
© Georg Thieme Verlag Stuttgart · New York

Synthesis of Novel Polyhydroxylated Tetrahydropyranopyrroles

Sébastien Nauda, Muriel Pipeliera, Christophe Chaumettea, Guillaume Viaulta, François Huetb, Stéphanie Legoupyb, Didier Dubreuil*a
a Université de Nantes, CNRS, Laboratoire de Synthèse Organique, UMR 6513, Faculté des Sciences et des Techniques, 2 Rue de la Houssinière, BP 92208 44322 Nantes Cedex 3, France
Fax: +33(2)51125402; e-Mail: didier.dubreuil@univ-nantes.fr;
b Université du Maine, CNRS, Laboratoire de Synthèse Organique, UCO2M, UMR 6011, Faculté des Sciences et des Techniques, Avenue Olivier Messiaen, 72085 Le Mans Cedex 9, France
Further Information

Publication History

Received 21 September 2006
Publication Date:
07 February 2007 (online)

Abstract

The stereoselective access to original polyhydroxylated tetrahydropyranopyrroles is described. The key steps involve an ­inverse-demand Diels-Alder reaction and a ring contraction of a ­pyridazine heterocycle.

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Purification of 23 and 24 on silica gel is not recommended; otherwise, a mixture of cyclized and non-cyclized products could be obtained.

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NMR Data of (4 R ,5 S ,1′ R ,2′ R )-3-Butyl-4-hydroxy-2-methoxycarbonyl-7-oxo-5-(1′,2′,3′-trihydroxyprop-1′-yl)-1,4,5,7-tetrahydropyrano[3,4- b ]pyrrole [(4 R )-26].
1H NMR (400 MHz, CD3OD): δ = 0.94 [t, 3 H, Hδ(Bu), 3 J = 7.3 Hz], 1.40 [m, 2 H, Hγ(Bu)], 1.50-1.67 [m, 2 H, Hβ(Bu)], 2.85 [m, 2 H, Hα(Bu)], 3.74 (dd, 1 H, H3 a, J 3 a-3 b = 11.5 Hz, J 3 a-2 = 6.6 Hz), 3.83 (dd, 1 H, H3 b, J 3 b-3 a = 11.5 Hz, J 3 b-2 = 4.0 Hz), 3.87 (s, 3 H, OMe), 4.00 (m, 1 H, H2 ), 4.19 (dd, 1 H, H1 , J 1 -5 = 7.9 Hz, J 1 -2 = 4.6 Hz), 4.56 (dd, 1 H, H5, J 5-1 = 7.9 Hz, J 5-4 = 2.1 Hz), 5.00 (d, 1 H, H4, J 4-5 = 2.1 Hz). 13C NMR (100 MHz, CD3OD): δ = 4.2 [Cδ(Bu)], 23.7 [Cγ(Bu)], 25.3 [Cα(Bu)], 34.3 [Cβ(Bu)], 52.1 (OMe), 60.7 (C4), 63.9 (C3 ), 72.1 (C1 ), 73.8 (C2 ), 84.1 (C5), 121.5, 126.2 (C2, C5), 130.8, 131.8 (C3, C4), 160.7, 162.5 (2 CO). HRMS: m/z calcd for C16H24NO8 [M + H]+: 358.1502; found: 358.1490. [α]D 20 +21.2 (c 1.65, MeOH).