An expedient and simple synthetic approach to pitavastatin and rosuvastatin final intermediates is described. The presented approach consists of completely stereoselective Julia–Kocienski olefination step (E/Z up to 300:1) between lactonized statin side-chain precursor and sulfone derivative of the corresponding pyrimidine and quinoline heterocyclic cores. The desired O-TBS protected statin lactones were isolated in 66–71% yield and high >97% purity (HPLC).
Key words
stereoselective synthesis - olefination - heterocycles - sulfones - lactones - aldehydes - drugs