CarbohydrateCarbohydrateYou will need to memorize the structures of the You will need to memorize the structures of the following monosaccharidesfollowing monosaccharides: :

تكون Dنضع فوق OHعندما CH2OHالموجودةوتعني اليمين ناحية اتجاه Dextroفي ان اى

الساعة عقارب اتجاه في الضوء .انحراف

L LevoL Levo : : بها التي المركبات في بها وتكون التي المركبات في األخيرة OHOHوتكون األخيرة قبل قبل. الشمال اتجاه .في الشمال اتجاه في

عدد آن عدد يالحظ آن األحادية = isomersisomersيالحظ السكريات األحادية = في السكريات 22nnفيعدد nnحيث حيث عدد هي ..asymmetric carbonsasymmetric carbonsهي

IIII. . GlucoseGlucose Structure elucidation of glucose:Structure elucidation of glucose:

1- Molecular formulae C6H12O61- Molecular formulae C6H12O6

22--

The reaction indicate that glucose contain carbonyl groups

3- Mild oxidation of glucose with bromine water gives 3- Mild oxidation of glucose with bromine water gives gluconic acid, also glucose gives positive with gluconic acid, also glucose gives positive with tollen’s reagent, this means that glucose contains –tollen’s reagent, this means that glucose contains –

CHO groupCHO group..4- Mild oxidation of glucose gives gluconic acid4- Mild oxidation of glucose gives gluconic acid

55--Strong oxidation gives glucaric acid (sacchric acid) Strong oxidation gives glucaric acid (sacchric acid)

This reaction indicates that glucose contain terminal primary alcohol

66--

The above reaction showed that glucose is not branched

7-7-

The reaction shows that glucose contains five –OH groups

8- glucose react with HCN to give cyanohydrin which 8- glucose react with HCN to give cyanohydrin which gives heptanoic acid on hydrolysis followed by gives heptanoic acid on hydrolysis followed by heating with HI heating with HI

From above reactions, glucose has the following From above reactions, glucose has the following structure.structure.

الحظ أن التفاعالت السابقة باإلضافة كونها تعتبر إثبات•فإنها تكتب أيضا في حالة طلب تفاعالت Glucose لتركيبGlucose يضاف إليها تفاعل تكوين وOsazone وأيضا

. تحويل الجلوكوز إلى سكريات أخرى التفاعالت التي يتم فيها

Action of phenylhydrazine on glucose and Action of phenylhydrazine on glucose and fructose (formation of Osazone):fructose (formation of Osazone):

(A) Glucose(A) Glucose

(B)(B) FructoseFructose

Question:Question:

write on the following:write on the following:

Action of phenylhydrazine on glucose.Action of phenylhydrazine on glucose.

Glucose and fructose give the same osazoneGlucose and fructose give the same osazone..

Complete the following equation:Complete the following equation:

Glucose + 3 PhNHNH2Glucose + 3 PhNHNH2

Conversion of glucose to fructose or conversion of Conversion of glucose to fructose or conversion of aldoses to ketosesaldoses to ketoses