ChemInform Abstract: Preparative Scale Stereoselective Synthesis of Methyl 4-Methyl-Z-2,4-pentadienoate

The title compound is prepared efficiently and stereoselectively by sodium methoxide induced Favorskii rearrangement and elimination of HBr from 4-methyl-1,3,4-tribromo-2-pentanone which is formed by direct bromination of mesityl oxide. The method provides mole quantities of the title compound.