STEREOSELECTIVE METHOD FOR THE PREPARATION OF NUCLEOSIDE ANALOGUES

摘要

A process for producing predominantly cis nucleosides or nucleoside analoguesand derivatives of formula (A): wherein R1 is a pyrimidine base or apharmaceutically acceptable derivative thereof and Q is oxygen, carbon orsulphur, comprising a coupling step of the pyrimidine base with a molecule offormula (B) described herein in a suitable coupling solvent, in the presenceof catalytic amounts of an element or combination of elements of groups 1B or11B of the periodic table, a tertiary amine and a Lewis acid to obtained anintermediate of formula (D) which is deprotected in the subsequent step togenerate the product of formula (A).