Citral

Citral is widely distributed and occurs to the extent of 70 to 80 percent in lemongrass oil.

Isolation

              The essential oil containing citral is treated With sodium bisulphite solution,when crystalline citral bisulphite derivative is obtained. This derivative is then hydrolyzed with sodium carbonate to give pure citral.

Chemical Structure of Citral

• Molecular Formula: C₁₀H₁₆O (monoterpene aldehyde).
• Isomers:
  • Geranial (trans-citral, E-isomer) – Strong lemon odor.
  • Neral (cis-citral, Z-isomer) – Milder, sweeter aroma.
• Functional Group: α,β-unsaturated aldehyde (reactive site).
• Spectroscopic Data:
  • IR: Strong peak at ~1680 cm⁻¹ (C=O stretch).
  • NMR: Characteristic aldehydic proton at ~9-10 ppm.

Structure of Citral

• Citral react with hydroxylamine to form an Oxime.
• 
• Citral reacts with bromine to form a tetrabromide dederivative.

              This indicated the presence of two C-C double bonds in the citral.

• Citral undergoes hydrolysis with potassium carbonate to give 2-methyl-2-hepten-6-one(Methylheptenone) and acetaldehyde.
• 

• When citral is heated with potassium bisulphate,it is convert to P-cymene.

Synthesis Of Citral (Barbier-Bouveaul-Tiemann’s)

Citral can be synthesis form 2-methyl-2-hepten-6-oneby the following three steps.

Step1:- Methyheptenone is subject to reformatsky reaction and hydrolysis to give a β-hydroxy acid.

Step2:- Dehydration of β-hydroxy acid   with anhydride give geranic acid.

Step3:-  Distillation of a mixture containing the calcium salts of geranic acid and calcium formate yields citral

• Determination
• Inorganic Chemistry
• Normality
• Organic Chemistry
• Physical Chemistry
• Reaction
• Uncategorized

Use Of Citral

• All About Vitamins Functions, Sources, Deficiencies And Sample Questions
• How to Determine Normality of Sodium Thiosulfate
• Preparation of 4% Neutral Boric Acid Solution
• Preparation and Titration of 0.2N HCl
• Full Hand Writing Copy Note Of Tin (Sn) with PDF