Question

On the basis of which evidences D-glucose was assigned the following structure?
`overset(" "CHO)overset(|)underset(" "CH_(2)OH)underset(|)(" "(CHOH)_(4))`

Answer 1

Evidences on the basis of which glucose was assigned the following structure are as follows
(i) Glucose on reaction with HI produces n hexane which indicates presence of six carbon atom linked in a having straight chain.
`C_(6)H_(12)O_(6)overset(HI)rarrn` hexane
(ii) Glucose on reaction with acetic anhydride produces glucose penta acetate which indicates presence of five OH groups.
`C_(6)H_(12)O_(6)overset(Ac_(2)O)rarr` Glucose pentaacetate
(iii) Glucose on oxidation with bromine water produces gluconic acid indicates presence of `-CHO` group.
Glucose `overset(Br_(2)//H_(2)O)rarr` Gluconic acid
(iv) Glucose on reaction with `HNO_(3)` produces saccharic acid which indicates presence of one primary OH group.