50. identify the major product of the following reaction conc. hso& a oh a (c)

sir we need to check the stability of carbonation after rearrangement or stability of alkene.

sourav here in both shift 3rd degree carbocation is formed but we have to consider the final product...then stability of alkene decides which is more stable and major one

got this sourav??

ok sir, you mean in dehydration reactions we need to see stability of alkene everytime over carbonation stability?

sourav if carbocation stability is same then ...as because if 2nd degree carbocation is there and 1st degree than obvious 2nd is more stable and product alkene is also most stable but if by doing both shift same degree carbocation occurs...then check stability of final product

the figure shown in answer and the figure drawn in qs are different.

we get stable 6 membered ring *if you are confused about second picture

five membered ring is another possibility but stability wise we go for 6 membered ring

if we remove hydrogen from 6th position or I remove methyl group from 2nd position, i will always get same degree carbonation for rearrangement. as we know hydride shift if major to methyl shift we should remove hydrogen from 2nd position and form the product.

but your answer is correct.

hope you understand the concept

bro you did methyl shift when there was a possibility of hydride shift. can you explain why you did it?

for more stability

bro check it first, same stable product are formed in hydride shift as well as methyl shift. Aslo hydride shift product is more stable.. check and tell

yes both shifts can occur but the question is about major product. so stability wise methyl shift gives more stability to product than hydride shift.

hydride shift gives you 7 alpha hydrogen while methyl shift gives you 6 alpha hydrogen.. isnt it?

first form the carbonation, then check for alpha hydrogens

into shift. it is not readily available. it needs a strong reagent to make that shift whereas the alkyl shift is easily possible and will provide a better stability. hence major product

bro hydride shift is priotize over methyl shift in carbonation rearrangement.