Question

Which set of terms correctly identifies the carbohydrate shown?
1. Pentose 2. Hexose 3. Aldose 4. Ketose 5. Pyranose 6. Furanose

• A. $1,3$ and $6$
• B. $1,3$ and $5$
• C. $2,3$ and $5$
• D. $2,3$ and $6$
• E. $1,4$ and $6$

Answer 1

Answer: (A)

This compound contains five carbon atoms, so it is a pentose. Its first carbon contains $-H$ and $-OH$ group. This suggests that it is an aldose (ie, contains aldehyde group). Since its structure is similar to furan (a heterocyclic compound), so it has furanose structure. Hence, this compound is a pentose, aldose and have furanose structure.