Question

The elimination of 5−bromononane on treatment with potassium ethoxide is stereoselective. Select the correct Newman projections of 5−bromononane showing the conformations that lead to cis−4−nonene and trans−4−nonene, respectively. Identify the proton that is lost in each case by selecting the Newman projections that have this hydrogen colored blue. Suggest a mechanistic explanation for the observed stereoselectivity. Leads to cis−4−nonene:

Answer 1

hey There!:

Compound B is the structure that leads to Cis-nonene as major product because in this case the Leaving group i.e Br and the electrophile i.e H is not anti-periplanar to each other .

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