Butane has four carbons with a chlorine atom on carbon two.
The chlorine atom can be in the front or the back.
Two stereoisomers can be drawn for two-chlorobutane. These are enantiomers because they have opposite configurations at their chiral centers and no internal plane of symmetry.
Pentane with a bromine atom on carbon two and a chlorine atom on carbon three.
Potentially up to four stereoisomers because there are two chiral centers (2n$$2^n$$ or 22=4$$2^2 = 4$$, where n$$n$$ is the number of chiral centers).
Bromine atom on a wedge and chlorine atom on a dash.
Change the stereochemistry of the first stereoisomer.
Compounds 1 and 2 are diastereomers because only one chiral center changed.
Change the chiral center with the bromine atom, putting the chlorine atom back on the wedge.
Compounds 1 and 3 are diastereomers because only one chiral center has changed.
Compounds 2 and 3 are enantiomers because both chiral centers have changed their configuration.
Put the bromine atom in the back and the chlorine atom in the back.
One and four are enantiomers (all chiral centers changed, no internal plane of symmetry).
Two and four are diastereomers (differ by only one chiral center).
Three and four are diastereomers.
Drawing all stereoisomers for this molecule, designating carbons one and two.
First stereoisomer.
Changing one of the chiral centers.
Compounds 1 and 2 are diastereomers.
Changing both chiral centers.
Compounds 2 and 3 are diastereomers.
Compounds 1 and 3 are meso compounds with an internal plane of symmetry, thus they are identical.
Last Stereoisomer
Compounds 2 and 4 are enantiomers because all chiral centers have changed and there's no internal plane of symmetry.
Compounds 1 and 3 are meso compounds (identical).
Compounds 1 and 2 are diastereomers.
Compounds 3 and 4 are also diastereomers.
Total of three stereoisomers (1, 2, and the meso compound).
Stereoisomerism - The Organic Chemistry Tutor
Butane has four carbons with a chlorine atom on carbon two.
The chlorine atom can be in the front or the back.
Two stereoisomers can be drawn for two-chlorobutane. These are enantiomers because they have opposite configurations at their chiral centers and no internal plane of symmetry.
Pentane with a bromine atom on carbon two and a chlorine atom on carbon three.
Potentially up to four stereoisomers because there are two chiral centers (2n or 22=4, where n is the number of chiral centers).
Bromine atom on a wedge and chlorine atom on a dash.
Change the stereochemistry of the first stereoisomer.
Compounds 1 and 2 are diastereomers because only one chiral center changed.
Change the chiral center with the bromine atom, putting the chlorine atom back on the wedge.
Compounds 1 and 3 are diastereomers because only one chiral center has changed.
Compounds 2 and 3 are enantiomers because both chiral centers have changed their configuration.
Put the bromine atom in the back and the chlorine atom in the back.
One and four are enantiomers (all chiral centers changed, no internal plane of symmetry).
Two and four are diastereomers (differ by only one chiral center).
Three and four are diastereomers.
Drawing all stereoisomers for this molecule, designating carbons one and two.
First stereoisomer.
Changing one of the chiral centers.
Compounds 1 and 2 are diastereomers.
Changing both chiral centers.
Compounds 2 and 3 are diastereomers.
Compounds 1 and 3 are meso compounds with an internal plane of symmetry, thus they are identical.
Last Stereoisomer
Compounds 2 and 4 are enantiomers because all chiral centers have changed and there's no internal plane of symmetry.
Compounds 1 and 3 are meso compounds (identical).
Compounds 1 and 2 are diastereomers.
Compounds 3 and 4 are also diastereomers.
Total of three stereoisomers (1, 2, and the meso compound).