JEE Advanced levelSingle correct optionDifficulty 3 of 3bm178
Methyl alpha-D-glucopyranoside is treated with excess periodic acid. Assume a ring-oxygen-bearing carbon is not cleaved, so the C-2, C-3, C-4 triol is cleaved at both C-C bonds, the middle carbon being released as formic acid, and the C-5 / C-6 bond is not cleaved because C-5 carries the ring oxygen and no free OH. The moles of HIOX4 consumed and of HCOOH formed per mole of glycoside are
A3 and 1
B2 and 2
C4 and 2
D2 and 1
Answer: D
The vicinal triol C-2/C-3/C-4 undergoes two C-C cleavages, each consuming one HIO4, so 2 mol HIO4. The middle carbon C-3 ends up as 1 mol HCOOH. No other cleavage occurs under the stated assumption.