New stereoselective synthesis of phosphono analogues of glycosyl phosphates

摘要

A new and stereoselective synthesis of isosteric phosphono analogues of glycosyl phosphates is reported. Appropriately protected glyconolactones, easily available from the parent sugars are reacted with ethyl-alpha-iodomethylphosphonate in THF in the presence of a soluble low-valent cobalt-phosphine complex, either in stoichiometric or sub-stoichiometric amounts, in the latter case in the presence of magnesium metal. The use of magnesium metal alone works, but in a less efficient and predictable way. The intermediate addition product can be subsequently deoxygenated with triethylsilane in the presence of boron trifluoride. (C) 2002 Elsevier Science Ltd. All rights reserved. [References: 28]