Synthesis of 5,6-dimodified open-chain D-fructose derivatives and their properties as substrates of bacterial polyol dehydrogenase

5-Deoxy-5-fluoro-D-xylulose as well as a range of new 5,6-dimodifed open-ch ain analogues of D-fructose, namely the 5,6-diazido-5,6-dideoxy, 6-azido-5, 6-dideoxy, 6-azido-5,6-dideoxy-5-fluoro, 5,6-dideoxy-5-fluoro, 5,6-dideoxy- 6-fluoro and 5,6-dideoxy-5,6-difluoro derivatives, were synthesised employi ng glucose isomerase catalysed isomerisation of the corresponding D-xylo- a nd D-glucofuranoses as a key step. New compounds as well as some previously reported analogues such as 5-azido-5,6-dideoxy-6-fluoro-D- fructose were s hown to be excellent substrates of polyol dehydrogenase from Burkholderia c epacia DSM 50181 with K-m values two orders of magnitude smaller than the c orresponding natural substrates. (C) 2000 Elsevier Science Ltd, All rights reserved.