Synlett 2009(14): 2325-2327  
DOI: 10.1055/s-0029-1217715
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Easy Silica Gel Supported Desymmetrization of PEG

Barbara La Ferla*, Cristiano Zona, Francesco Nicotra
Department of Biotechnology and Bioscience, University of Milano Bicocca, Piazza della Scienza 2, 20126 Milano, Italy
Fax: +39(026)4483565; e-Mail: barbara.laferla@unimib.it;
Further Information

Publication History

Received 26 February 2009
Publication Date:
31 July 2009 (online)

Abstract

Our work shows how poly(ethylene glycol), differentially functionalized at two ends, can be easily and efficiently synthesized from commercial symmetric dihydroxy PEG 600. First, we linked the polymer onto functionalized silica gel using one of its ­hydroxy ends. Then, the second hydroxy group was modified, and finally, the desymmetrized PEG was cleaved from the solid support.

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The loading was calculated by treating 1 g of pegylated silica gel 3 with cleavage solution and weighting the recovered PEG.

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Analytical sample was treated with NaBH4 and analyzed with mass spectrometer. ESI-MS (most intense peaks): (n = 10) 541.4 [M + Na+]; (n = 11) 585.4 [M + Na+]; (n = 12) 629.9 [M + Na+].