Which carbon atom of glucopyranose numbered from C -1 to C -6 is anomeric?

Step-by-step solution

The anomeric carbon in cyclic sugars originates from the carbonyl carbon in the open-chain form. In glucose, an aldohexose, the aldehyde group is located at C -1 . During cyclization to form glucopyranose, the C -1 aldehyde carbon reacts with the hydroxyl group at C -5 , forming a hemiacetal. This positions C -1 as bonded to both the ring oxygen and the anomeric hydroxyl group. C -1 becomes chiral upon ring formation and serves as the anomeric carbon. The correct identification is D .