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Hello students.
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In this question we are looking at conversion of vanolin to vinyl alcohol under the presence of sodium borohydra.
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So i'll draw the structure for vanolin.
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So it has a benzene ring with a phenol, nano ester, and an aldehyde.
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Now the hydroxyl ion from noh goes and attacks on this oxygen and removes the hydrogen.
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Hydrogen.
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So we get an intermediate state where the positive charge ends on the phenolic oxygen.
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And here is the estra group and the aldehyde group.
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Now the hydride ion from n -a -b -h -4 goes and attacks this carbon and this double bond goes on the oxygen.
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So we get a intermediate state where the hydride ion from nabh4 has been attached to carbon.
01:30
So i will give this a special color h.
01:34
Now what happens is this oxygen negative charge goes and attacks bh3 and gives an intermediate state where estrogen where boron and and oxygen forms a covalent bond.
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So, okay? now, this reaction is repeated three times to form the most stable intermediate compound, intermediate state where boron has four of these activated vinylum.
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Ch3, c, this h is special because it is coming from hydride, here also, this is special.
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This is special and this o and here it is repeated three times.
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The total number comes out to be 4.
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Now what happens is this poron has a negative charge on it.
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Now this reaction undergoes protonation with hcl provided in water.
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So hcl breaks down into h plus plus cl minus.
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So i will give the black color to h here.
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So this goes and attacks this boron and also this oxygen.
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So we get a state where vinail alcohol is formed like this...