Chemistry of Butanediolic Acid
Stereochemistry of Butenedioic Acid
Objective: To study the interconversion of two geometric isomers, maleic acid (cis isomer) to fumaric acid (trans isomers), the differences in physical properties between this pair of cis-trans isomers and determine the stereochemistry of addition of bromine to butenedioic acid.
Chemicals and Apparatus:
2 grams of maleic acid, 10 cm3 of concentrated hydrochloric acid, 10 cm3 of bromine water[1], one 50 cm3 beaker, one 100 cm3 beaker, one
250 cm3 beaker, one 10 cm3 measuring cylinder, one piece of spatula, one piece of water glass, one glass rod, a few pieces of filter paper, a set of Buchner funnel, a filter flask with side tube, three glass capillary tubes, a set of melting point apparatus, one long hollow glass tubing, one electronic balance, one heater and the oven
Background:
Stereochemistry is always encountered throughout organic chemistry.
And stereochemistry isomerism can be divided into two classes, geometrical isomerism and optical isomerism. Although these categories are not mutually exclusive, it is not uncommon to find compounds that exhibit only one or the other of the two types. Most geometrical isomers result from cyclic systems or restricted rotation about double bonds. The preparation of fumaric acid by isomerization of maleic acid and addition of molecular bromine to fumaric acid was illustrated in the experiment.
Geometric isomers can be interconverted if the double bond is temporarily converted to a single bond, about which rotation is relatively free. For example, an electrophile adds to the double bond, rotation becomes possible. Loss of the electrophile then regenerates the double bond. If rotation occurred in the intermediate, the result is the other isomer.
The result of this kind of transformation is an equilibrium mixture of the cis and trans isomers. Frequently, the trans isomer is more stable, so the equilibrium mixture would contain more of the trans
Objective: To study the interconversion of two geometric isomers, maleic acid (cis isomer) to fumaric acid (trans isomers), the differences in physical properties between this pair of cis-trans isomers and determine the stereochemistry of addition of bromine to butenedioic acid.
Chemicals and Apparatus:
2 grams of maleic acid, 10 cm3 of concentrated hydrochloric acid, 10 cm3 of bromine water[1], one 50 cm3 beaker, one 100 cm3 beaker, one
250 cm3 beaker, one 10 cm3 measuring cylinder, one piece of spatula, one piece of water glass, one glass rod, a few pieces of filter paper, a set of Buchner funnel, a filter flask with side tube, three glass capillary tubes, a set of melting point apparatus, one long hollow glass tubing, one electronic balance, one heater and the oven
Background:
Stereochemistry is always encountered throughout organic chemistry.
And stereochemistry isomerism can be divided into two classes, geometrical isomerism and optical isomerism. Although these categories are not mutually exclusive, it is not uncommon to find compounds that exhibit only one or the other of the two types. Most geometrical isomers result from cyclic systems or restricted rotation about double bonds. The preparation of fumaric acid by isomerization of maleic acid and addition of molecular bromine to fumaric acid was illustrated in the experiment.
Geometric isomers can be interconverted if the double bond is temporarily converted to a single bond, about which rotation is relatively free. For example, an electrophile adds to the double bond, rotation becomes possible. Loss of the electrophile then regenerates the double bond. If rotation occurred in the intermediate, the result is the other isomer.
The result of this kind of transformation is an equilibrium mixture of the cis and trans isomers. Frequently, the trans isomer is more stable, so the equilibrium mixture would contain more of the trans