Question

40) Provide the major organic product of the reaction shown below. CHs но'. Нас осн,сH, CH&CH,CO

Answer 1

First step should be the protonation of the etheral oxygen, because that is more fateful,

CH3 Hgc V CH HC H2CH,COCO CH,CH; H,CH_COCA ÇHCH

Now there can be three possibility,

1. S_N2 on the carbon 1 and leaving of alcohol. But that carbon is so much conjested that, provision of S_N2 is very low.

2. Elimination using H of C2. But this will also have very low possibility. The protons are not at all acidic, thus in acidic medium abstraction of them is quite difficult.

3. S_N2 on carbon 3. This is least conjested carbon and H₂O will attack here, leaving the left part. The product will be the same as that from 1. But the mechanism will follow this way.

CH, H+ CH3 HzCW H3C X нусн,сосон H2CH,COC H20: CH3 нсон

Now, heating condition will lead to dehydration by following mechanism:

CHz Hzc X H3CH,COCOH HJC H3CH,COCOH Н3С- COCH2CH3

This will be the product because of the less sterically hindered, Newman projection:

OH2 Same side H₃th → H3CH2C c OCH2CH3 H