Provided are intermediates useful for the synthesis of hydroxyl-alkyl substituted azetidinones, processes of their preparation, and processes for the synthesis of certain hydroxyl-alkyl substituted azetidinones. Also provided are processes for the synthesis of 1-(4-fluorophenyl)-3(R)-[3-(4-fluorophenyl)-3(S)-hydroxypropyl]-4(S)-(4-hydroxyphenyl)-2-azetidinone, or ezetimibe.