Cross Condensation Of Aldol Lab Report

Cross Condensation of aldol
2015007632
Dowrie, K
Contents
Reaction 1
Introduction 1
Experiment Procedure 2
Experimental results 3
Table of calculations 3
Calculations 3
NMR 4
TLC 4
References 5

Reaction

Introduction
An aldehyde reaction is when aldehydes and keytones, both containing an α-hydrogen in the presence of an alkali group condenses and forms an enone. Acetone has α-hydrogens on each side. The proton can be removed and therefore giving a nucleophile anion. The aldehyde carbonyl is more reactive than the keytone and so it reacts rapidly with the anion. This product undergoes base catalysed hydration giving dibenzalacetone. Sodium hydroxide is a catalyst in the reaction because the NaOH reacts with water. Following this is then the

While under the UV light the mixtures appeared a purple colour.
The R_fValue
Starting material: R_F=2.6/4.5 = 0.58
The sum: R_F=2.55/4.5 = 0.57
The reaction mixture: R_F=2.9/4.5 = 0.64
The final product: R_F=1.9/4.5 = 0.42

Table of calculations Benzaldehyde Acetone Sodium Hydroxide Ethanol Dibenzalacetone
Co-efficient 2 1 1 1 1
Volume (ml) 4.04 1.5 30
Grams used (g) 4.2 1.185 4 0.95 2
Formula weight (g/mol) 106.12 58.08 40 46.07 234.29
Moles 0.0396 0.02 0.1 0.02
Moles/ Coefficient 0.02 0.02 0.1 0.02
Density 1.04 0.79
(1)
Calculations
Mass
Impure compound mass: 2.02g
Final compound mass: 2.88g

Dibenzalactone = (4.2×234.29×1)/(106.12×2) = 4.64g
(theoretical

This process is to separate the substances within the compound. The compounds that are absorbed more travel less distance on the paper. The paper contains silica gel and the compounds stick to it as it travels up the paper. A very important aspect of TLC is to have a base line where all the compounds start from. As well as the ending line, where the solvent stopped. The higher the compounds go up the more polar the substance is. (1) On the TLC that was done in the practical 1 two lines had roughly the same distance of 2.55-2.6cm. The reaction material was higher of about 2.9cm and the final product was lower (1.9cm). This means that the reaction materials had a higher polarity than the other 3. The final product had the lowest polarity. The TLC drawing is