Modular Synthesis of Constrained Ethyl (cEt) Purine and Pyrimidine Nucleosides

A modular
and scalable approach to pyrimidine- and purine-containing
constrained ethyl (cEt) nucleosides is demonstrated. Minimizing stereochemical
adjustments and protecting group manipulations, diacetone glucose
is converted to two representative cEt nucleosides via a functionalized,
common intermediate. The retrosynthetic approach to this complex class
of drug precursors offers clear benefits over existing routes based
on step count and efficiency.