A mastery over several such techniques enables the molecular architect (popularly known as organic chemist) to achieve the challenging task of synthesizing the myriade of molecular structures encounte...A mastery over several such techniques enables the molecular architect (popularly known as organic chemist) to achieve the challenging task of synthesizing the myriade of molecular structures encountered in Natural Products Chemistry, Drug Chemistry and modern Molecular Materials. In this task, organic chemists are further guided by several ‘thumb rules’ that chemists have evolved over the past two centuries.