Experiment 6 - Stereochemistry - Molecular Models

stereochemistry

involves the study of molecules in 3D space

stereoisomers

isomers that differ ONLY in spatial arrangement of atoms

bond angles of tetrahedral atom

109.5 degrees

chiral center

carbon atom with 4 different groups bonded to it

chemical and physical properties of enantiomers vs. diastereomers

• enantiomers

  • almost identical chemical and physical properties

  • differ in stereochemistry

• diastereomers

  • differ in stereochemistry, chemical properties, and physical properties

eclipsed vs. staggered conformers

• eclipsed - hydrogens brought as close together as possible

  • higher energy and less stable

• staggered - hydrogens are far away from one another

  • lower energy and less stable

2 preferred conformations of a cyclohexane

chair and boat

• chair is ore stable

• in chair conformation, all C-H bonds are either axial or equatorial

which carbon is chiral

• carbon A and B

which of the following are the two chiral structures for 1-chloro-2-bromopropane

I and II

are the two following structures identical, enantiomers, stereoisomers, structural isomers?

• enantiomers and stereoisomers

are these identical, enantiomers, stereoisomers, and/or structural isomers?

structural isomers

• they show different bonding

are these structures identical, enantiomers, stereoisomers, and/or structural isomers

• enantiomers and stereoisomers

  • since they are mirror images of each other

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

• since they are not superimposable and not mirror images of each other

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

• sincee they are not superimposable and not mirror images

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

enantiomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

enantiomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

enantiomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

diastereomers and stereoisomers

are these structures identical, enantiomers, diastereomers, stereoisomers, and/or structural isomers?

identical

which of the alkenes is in its Z geometric isomer form?

C

which of the following are axial bonds on the cyclohexane

B and D

which of the following is a correct statement

1. bonds A and C are 1,2-cis

2. bonds A and B are 1,3-cis

3. bonds C and B are 1,3-cis

4. bonds A and D are 1,3-trans

5. bonds C and D are 1,2-trans

4. bonds A and D are 1,3-trans