合成路线1

Two new related proceases to synthesize simvastatin have been described: 1) The reduction of the lactone function of lovastatin (I) with diisobutylaluminum hydride (DIBAL) in THF/dichoromethane gives the hemiacetal (II), which by reaction with acetyl chloride in methanol yields the acetal (III). The methylation of (III) with methyl iodide by means of BuLi and pyrrolidine in THF affords the 2,2-dimethylbutyric acid ester (IV), which is treated with HCl in THF to give the hemiacetal (V). Finally, this compound is oxidized with Ag2CO3 in refluxing toluene. 2) The direct methylation of hemiacetal (II) with methyl iodide by means of BuLi and pyrrolidine in THF directly yields the methylated herniacetal (V) although with a little bit less purity.