Organic Chemistry Flashcards
Isomer
Two or more compounds with the same formula but different arrangement of atoms and different properties
Constitutional Isomers
Different nature/sequence of bonds
Stereoisomers
Different arrangement of groups in space
Types of stereoisomers
Conformational and Configurational
Conformational Isomers
Differ by rotation about a single bond
Configurational Isomers
Interconversion requires breaking bonds
Note: Don’t need to have double bonds to have configurational isomerism (can be in ring)
Types of configurational isomers
Enantiomers and Diastereoisomers
Enantiomers
Non-superposable mirror images
Note: superposable means exact replica
Diastereoisomers
Not mirror images
Diastereomer (Z)
Z double bond = together
High priority groups on same side of C=C
Diastereomer (E)
E double bond = opposite
High priority groups on opposite sides of C=C
Diastereomer (cis)
cis = same side (3D) = Z = together
Diastereomer (trans)
trans = opposite side (3D) = E = opposite
Inductive Effect
Carbocation stability
Alkyl groups help to spread the positive charge a little along the bonds.
In tertiary - charge spread over 3 more carbon atoms
Hyperconjugation
Carbocation stability
Adjacent C-H bonds donate a little electron density through space.
In tertiary - vacant p orbital receives partial donation of electrons from 9 possible C-H bonds
Mass spectrometry
Determines molecular formula