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The p- toluenesulfonate ( tosylate) esterdepicted in Scheme Q4 (a) iv undergoeselimination to form an alkene in thepresence of DBU (1,8- diazabicyclo15. 4.0Undec - 7- one )NO2ONCH3Cha+CH3-Tol(DBU)CH3O;S-TelTosylate esterScheme Q4(a)ivBy Stating the Stereochemical arrangmentrequired for this elimmation, explain whytosylate, elimination, explain unlikeSelenoside elimmation is successfulin this case .