Synthesis 2003(2): 0255-0261
DOI: 10.1055/s-2003-36815
PAPER
© Georg Thieme Verlag Stuttgart · New York

Syntheses of Guanidinoglycosides with the Inventive use of Mitsunobu Conditions­ and 1,8-Diazabicyclo[5.4.0]undec-7-ene

Peishan Lin, Sabrina Cher Hui Heng, Mui Mui Sim*
Institute of Molecular and Cell Biology, 30 Medical Drive, Singapore 117609, Singapore
Fax: +6567791117; e-Mail: muimui@merlionpharma.com;
Further Information

Publication History

Received 15 July 2002
Publication Date:
22 January 2003 (online)

Abstract

A series of novel guanidinoglycosides was successfully synthesized. This was accomplished with the use of Mitsunobu conditions as a strategy to convert the glycopyranose anomeric hydroxy group to give the corresponding substituted masked guanidines in high yields. Subsequent deprotection and coupling with Fmoc protected β-amino acid, afforded a series of N,N′-substituted-methylisothioureas. Cleavage of Fmoc followed by concomitant cyclization was achieved with a catalytic amount of DBU to give the guanidinoglycosides.

1

First and second authors contributed equally to this work.

12

To further prove the existence of rotomers, Boc-protection of 2 was carried out using Boc2O and DMAP in CH2Cl2. Both 2a and 2b yielded only their respective α rotomers.