An enantioselective synthesis of voriconazole.

A new seven-step sequence to access voriconazole, a clinically used antifungal agent, was developed. The initial catalytic asymmetric cyanosilylation is the key to constructing the consecutive tetra- and trisubstituted stereogenic centers. The fluoropyrimidine unit frequently triggered unexpected side reactions, but careful amendment of the reaction sequence allowed for the concise enantioselective synthesis.