A concise, efficient and production-scale synthesis of a protected L-lyxonolactone derivative: An important aldonolactone core

摘要

A multikilogram-scale synthesis of L-lyxonolactone- 2,3-O-isopropylidene is reported. It proceeds efficiently from an optimized, large-scale, aqueous bromine oxidation of D-ribose to D-ribonolactone including a one-pot isopropylidene formation, and subsequent conversion of the D-ribonolactone-2,3-O-isopropylidene to L-lyxonolactone-2,3-O- isopropylidene via the derived C-5-mesylate and intramolecular relactonization of the product of aqueous potassium hydroxide cleavage of the D-ribonolactone ring. The inversion of configuration at the C-4-chiral center is understood in terms of an intermediating C4C5- epoxide. The overall process is noteworthy for its operational simplicity, stereochemical integrity, and use of inexpensive chemicals.