Stereoselective Preparation of 1-[5-O-(tert-Butyldimethylsilyl)-2,3-dideoxy-3-iodo-β-D-threo-pentofuranosyl]thymine from Thymidine: An Efficient Entry to 3′,4′-Unsaturated Nucleoside

Abstract

The title compound (13) has been synthesized from 5′-O-TBS-thymidine (8) through a highly stereoselective iodination of the 3′-hydroxyl group utilizing I₂/PPh₃/imidazole. This method provides an efficient entry to the 3′,4′-unsaturated derivative (7).

Keywords:

• Iodination
• stereoselectivity
• thymidine
• 3′,4′-unsaturated nucleoside

Notes

^a All reactions were carried out by using I₂ (1.5 equiv), PPh₃ (1.5 equiv), and imidazole (2.0 equiv) in the respective solvent (concentration of 8: 56 mM).

^b The ratios were determined based on ¹H NMR spectroscopy by integrating H-1′.