How the open-chain structure of glucose was provedग्लूकोस की खुली श्रृंखला संरचना कैसे सिद्ध हुईHow the open-chain structure of glucose was proved
Class 12 Chemistry · Chapter 10 · interactive diagram
Parts and what they mean
- Glucose, CHO–(CHOH)₄–CH₂OH (ग्लूकोस, CHO–(CHOH)₄–CH₂OH) — Molecular formula C₆H₁₂O₆; an aldohexose (also called dextrose). Each reaction around it proves one feature of this structure.
- Prolonged heating with HI → n-hexane (HI के साथ देर तक गर्म करने पर → n-हेक्सेन) — CH₃–CH₂–CH₂–CH₂–CH₂–CH₃ forms, so all six carbons are linked in a straight chain.
- With hydroxylamine → oxime (हाइड्रॉक्सिलऐमीन से → ऑक्सिम) — –CHO + NH₂OH → –CH=N–OH + H₂O. Confirms a carbonyl group (>C=O).
- Adds HCN → cyanohydrin (HCN जुड़कर → सायनोहाइड्रिन) — –CHO + HCN → –CH(OH)CN. Also confirms the carbonyl group.
- Bromine water → gluconic acid (ब्रोमीन जल → ग्लूकोनिक अम्ल) — A mild oxidising agent turns –CHO into –COOH: HOOC–(CHOH)₄–CH₂OH, a six-carbon acid. So the carbonyl is an ALDEHYDE group.
- Acetic anhydride → glucose pentaacetate (ऐसीटिक ऐनहाइड्राइड → ग्लूकोस पेन्टाऐसीटेट) — Five acetyl groups go on: five –OH groups. As glucose is a stable compound, the five –OH must be on different carbons.
- Nitric acid → saccharic acid (नाइट्रिक अम्ल → सैकेरिक अम्ल) — Glucose and gluconic acid both give the dicarboxylic acid HOOC–(CHOH)₄–COOH. The –CH₂OH became –COOH, so glucose has a primary alcoholic (–OH) group.
Original diagram drawn by Simple Learning Hub, based on the NCERT textbook. Report a mistake