( a ) The synthesis shown below is unlikely to occur . Showing all structures and reaction mechanisms indicate what is wrong with this synthesis

Please provide some help for this question on the synthesis of following product.

( a ) The synthesis shown below is unlikely to occur . Showing all structures and reactionmechanisms indicate what is wrong with this synthesis ?"BYCH 2CH 2NBShu , CCIACH 3CH 3( 6 ) Showing all necessary structures and mechanisms indicate why it is not possible to prepare aGrignard reagent from 4 - bromo - 1 - pentanol ?