However many of these schemes are unpractical

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Unformatted text preview: s the majo rity of jobs for fresh graduates. However, this industry is characterized by multi -step syntheses, during which large amounts of waste are produced. The peculiarities of the pharmaceutical approval process require that the process is fixed very early in development. Consequently, the potential synthesis schemes have to be evaluated at a very early stage for their environmental impact in order to come up with a ‘green by design’ process. This necessitates the availability of proper tools to evaluate competin g reaction sequences with regards of their potential environmental impact . Various indicators have been proposed, such as Trost’s “atom economy” and Sheldon’s E -factor. The presentation will address the problems in generating metrics which make it possible to quantitatively assess ‘green-ness’. Such metrics should not only be based on weights and volumes, but should also consider toxicology and environmental impact as well as economic factors and the elegance of a synthesis. The talk will discuss the problems connected with integrating the concepts of green chemistry in undergraduate and graduate curriculum, and introduce different metrics that have been proposed, mostly by researchers in industry. 47 23rd-25th June 2010 3rd ICYC 2010 Universiti Sains Malaysia KN-08 CASCADE CATALYSIS: A GREEN APPROACH TO THE FORMATION OF MENTHOLS AND 4ALKYLCYCLOHEXANOLS Gaik-Khuan Chuah National University of Singapore, Kent Ridge, Singapore 117543 E-mail: [email protected] Catalytic cascade conversions are increasingly considered for organic syntheses d ue to savings in time, energy and materials. Such conversions eliminate the recovery of intermediates, while the presence of a catalyst minimizes the need for stoichiometric amounts of reagents, thereby reducing the wastes generated. The one-pot transformation of citral to menthols involves a triple cascade of hydrogenation, isomerization and hydrogenation steps. Due to the side products that can be formed, the first step in this route requires a highly selective route where the conjugated C=C bond in citra l is first hydrogenated to form ()-citronellal. C=O...
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