Synlett 2006(20): 3507-3509  
DOI: 10.1055/s-2006-956495
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Direct Entry to Carbasugars: Asymmetric Synthesis of 1-epi-(+)-MK7607

Christoph Grondal, Dieter Enders*
Institut für Organische Chemie, RWTH Aachen University, Landoltweg 1, 52074 Aachen, Germany
Fax: +49(241)8092127; e-Mail: Enders@rwth-aachen.de;
Further Information

Publication History

Received 25 September 2006
Publication Date:
08 December 2006 (online)

Abstract

A short and flexible synthesis of 5a-carbasugars is presented. The combination of a proline-catalyzed aldol reaction and a ring-closing metathesis affords 1-epi-(+)-MK7607 in seven steps with an overall yield of 23%.

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Analytical Data of 3.
R f = 0.15 (EtOAc-MeOH = 6:1); [α]D 22 232.7 (c 1.25, H2O). 1H NMR (300 MHz, D2O): δ = 3.49 (dd, J = 10.9, 4.2 Hz, 1 H), 3.59 (dd, J = 10.9, 7.4 Hz, 1 H), 4.03 (m, 1 H), 4.09 (m, 2 H, CH2OH), 4.16 (d, J = 4.2 Hz, 1 H), 5.66 (m, 1 H, C=CH) ppm. 13C NMR (75 MHz, D2O): δ = 61.8 (CH2OH), 66.5, 70.7, 71.7, 72.3 (CHOH), 126.9 (C=CH), 137.5 (C=CH). MS (EI, 70 eV): m/z (%) = 140 (7), 122 (10), 116 (47), 111 (28), 99 (17), 98 (100), 97 (21), 83 (11), 81 (13), 71 (11), 72 (14), 69 (27), 55 (15). HRMS: m/z calcd for C7H12O5 - 2H2O [M+ - 2H2O]: 140.04734; found: 140.04735.