Question

Identify total number of chiral centre present in product of following reaction :

Answer 1

4

Answer 2

The reaction involves the ring opening of the cyclic ether (furanose) by oxymercuration in methanol, followed by demercuration with NaBH4. This process cleaves a C-O bond in the ring, adds a methoxy group (from methanol) to one carbon and a hydrogen atom (from NaBH4) to the other carbon of the cleaved bond, while the ring oxygen becomes a hydroxyl group. Assuming the ring opens and forms a linear molecule, there are two possible products depending on which C-O bond is cleaved (C1-O or C4-O) and where the methoxy group adds. In either case, the resulting linear molecule is a derivative of a pentose with an OMe group and four carbons (C1 to C4) that are attached to four different groups, making them chiral centers. The C5 carbon (CH2OH) is not chiral. Therefore, the total number of chiral centers in the product is 4.

The final answer is $\boxed{4}$.