Question

19. Determine the major product from the following reaction sequence. 5 points i. HBF, H, COOCH, a 소 b HoL C. ii. KO'Bu, 'BuOH, A OH OH (CH3),C=CHCH, ? iii. BH, THE d e. НО. iv. H,O, NaOH OH a b с d e

Answer 1

In the first step an organic peroxide is used , CH3OOCH3 (dimethyl peroxide) for the addition of HBr in an unsymmetrical alkene is actually a radical initiator and adds the HBr in an anti- Markownikov's manner, i.e., H will add to the carbon with more alkyl substitution and Br will add to the less alkyl substituted carbon.

In the second step the base added is tertiary butoxide is a strong and bulky base used for dehydrohalogenation and preferably abstract the sterically less hindered beta- H atom and leads to the less substituted product.

And the last two steps are actually hydroboration- oxidation reaction which leads to the syn addition of water in an an anti- Markownikov's manner. i.e. OH group to the less substituted side of the unsymmetrical alkene.

ANSWER- Option (e)

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