Chlorine removal strategy

A less efficient approach to the )S-amino acid 193 a included initial reductive removal of the chlorine followed by hydrolysis of the ester and hydrogenolytic deprotection of the amino group (Scheme 57) [9]. Although the overall yield of 193 a was only 19 %, this strategy appeared to be appropriate also for application towards the Michael adducts of substituted 2-chloro-2-cyclopropylideneaceta-tes 2-R (see below). 

Recent trials on laboratory, pilot and full-scale plant have tended to confirm the lack of a beneficial effect on PCDD/F emissions, when chlorine-containing components of MSW and other waste types are withdrawn from the feedstock to a combustor.29,30 As a strategy for controlling PCDD/F formation, our view is that removal of chlorine-containing materials such as PVC is unlikely to prove effective. 

Strategy. The only structural difference between these two molecules is the replacement of two chlorine atoms on DDT with two methoxy (also written as OCH3) moieties on methoxychlor. Thus, we can use the pi-values of these two groups to first remove the two chlorines and then add the two methoxys. 

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