Synthesis 2010(15): 2533-2542  
DOI: 10.1055/s-0029-1218828
PAPER
© Georg Thieme Verlag Stuttgart ˙ New York

Synthesis of a Carbohydrate-Derived 1-Oxaspiro[4.4]nonane Skeleton and Its Conversion into Spironucleosides

Joy Krishna Maitya, Basudeb Acharia, Michael G. B. Drewb, Sukhendu B. Mandal*a
a Chemistry Division, Indian Institute of Chemical Biology (a unit of CSIR), Jadavpur, Kolkata 700032, India
Fax: +91(33)24735197; e-Mail: sbmandal@iicb.res.in;
b Department of Chemistry, University of Reading, Whiteknights, Reading, RG6 6AD, UK
Further Information

Publication History

Received 29 March 2010
Publication Date:
17 June 2010 (online)

Abstract

An easy entry to the 1-oxaspiro[4.4]nonane skeleton has been developed starting from a d-glucose-derived substrate. The key steps involve (a) installation of olefin moieties at the appropriate places through simple transformations and (b) construction of spiro rings by utilizing ring-closing metathesis reactions between these olefin functionalities. Subsequent deprotection of the acetonide­ functionality, peracetylation, nucleosidaton under Vorbrüggen­ reaction conditions, and final deprotections result in the formation of the spironucleosides. The involvement of an interesting intra/intermolecular acetyl migration has been used to rationalize the product distribution during desilylation. Various 1D and 2D NMR techniques and X-ray analyses of some important intermediates were used for assigning the structures and stereochemistry of the products.

21

CCDC 745578 (for 18) and CCDC 745579 (for 29) contain the supplementary crystallographic data for this paper. These data can be obtained free of charge from The Cambridge Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.