JEE Main 2022 (26 Jul, Shift 1) Chemistry Q79: Carbohydrates

Question

Which one of the following is a reducing sugar ?

Accepted Answer

Option 1: [figure: vertical chain of five carbons: top C with H and OH (OH at upper right), then H-C-OH, HO-C-H, H-COH (printed so), and bottom C with H below; a ring-closing line through O at the right connects the top C to the bottom C]

Answer

[figure: vertical chain of five carbons: top C with H and OH (OH at upper right), then H-C-OH, HO-C-H, H-COH (printed so), and bottom C with H below; a ring-closing line through O at the right connects the top C to the bottom C]

Answer

[figure: five-membered ring with O at top; HOCH2 on the upper-left ring carbon, H on the upper-right ring carbon with $\mathrm{OCH_3}$ on it; H, H, H labels on the ring carbons; OH and OH at the bottom ring carbons]

Answer

[figure: two five-membered rings (each with ring O at top) joined by a single O linking the right-hand carbon of the left ring to the left-hand carbon of the right ring; left ring has $\mathrm{HOH_2C}$, H, H, H, OH, OH; right ring has H, $\mathrm{CH_2OH}$, H, H, H, HO, OH]

Answer

[figure: open-chain vertical structure: top $\mathrm{OCH_3}$; then H / $\mathrm{OCH_3}$, H / OH, HO / H, H / OH, H / OH; bottom $\mathrm{CH_2OH}$]

JEE Main 26 July 2022, Shift 1, Chemistry Q79

Same idea in other shifts