write the open chain structure of glucose.

1.	write the open chain structure of glucose.
Answer» Solution :(1) Elemental analysis and molecular weight determination show that molecular formula of glucose is `C_(6)H_(12)O_(6)`. (2) Complete reduction with Hydrogen Iodide and Red Phosphorus gives n-hexane,which indicates that carbon atoms in glucose are in straight CHAIN. (3) Glucose reacts with acetic anhydride to form penta acetyl derivative which shows the presence of 5-OH groups in glucose. (4) Glucose reacts with hydroxylamine to form an glucose oxime which indicates the presence of > C = 0 (keto) group in glucose. (5) On MILD oxidation with bromine water glucose is converted to gluconic acid, when reduced with excess of Hl yields n-hexanoic acid. `C_(5)H_(11)O_(5)CHOunderset(fol)to C_(5)H_(11)O_(5)COOHunderset(11)toCH_(3) (CH_(2))_(4) COOH` gluconic acidn-hexanoic acid This clearly shows that glucose CONTAINS 6 carbon atoms in a straight chain with -CHO at one end, which gives -COOH on oxidation. (6) Based on the above reaction glucose open - chain structure can be given as follows: From the above structure the IUPAC name of glucose is 2,3,4,5,6 Pentahydroxyhexanal.

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