Organic Chemistry Fundamentals and Reaction Mechanisms

Practice flashcards covering organic chemistry nomenclature, stereochemistry, reaction mechanisms (radical and addition), and functional groups identified in the lecture notes.

Syn-addition

The addition of two atoms or groups to the same side of a double or triple bond, such as seen in the reaction of 1,2-diethylcyclopentene with $H_2$ to form cis-1,2-diethylcyclopentane.

Anti-addition

The addition of atoms to opposite sides of a double bond, resulting in a trans configuration, such as when cyclobutene reacts with $Br_2$ in $CCl_4$ to form trans-1,2-dibromocyclobutane.

Formal Charge (FC)

Calculated by the formula: $FC = \text{group number} - \text{unshared electrons} - \text{number of bonds}$. For example, in $CH_3 - N = N = N$, the nitrogen atoms from left to right have charges of $0$, $+1$, and $-1$.

Primary Carbon

A carbon atom that is bonded to only one other carbon atom.

Secondary Carbon

A carbon atom that is bonded to two other carbon atoms.

Tertiary Carbon

A carbon atom that is bonded to three other carbon atoms.

Markovnikov's Rule

A rule stating that during addition reactions, the hydrogen ($H$) will preferentially add to the carbon atom that is least substituted (has the most existing hydrogen atoms).

Initiation

The first step in a free radical mechanism where a bond is broken to form two radicals, such as $Cl-Cl \rightarrow \text{2 radicals}$.

Propagation

The stage of a radical mechanism where a radical and a neutral compound react to produce new bonds and maintain a radical state.

Termination

The final step in a radical mechanism where two radicals combine to form a neutral compound, ending the reaction chain.

2,2,4-trimethylpentane

The IUPAC name for the compound with the structural formula $(CH_3)_3C-CH_2-CH(CH_3)_2$.

4-propyl-4-octene

The IUPAC name for the hydrocarbon $(CH_3CH_2CH_2)_2C=CH-CH_2-CH_2-CH_3$.

Stereocenter

A chiral carbon atom bonded to four different single-bonded groups.

Stereoisomer Count Formula

A formula used to determine the number of possible stereoisomers for a molecule with $n$ stereocenters, defined as $2^n$.

Enantiomers

A pair of molecules that are non-superimposable mirror images of each other, such as 1R,2R-1,2-dimethylcyclopentane and 1S,2S-1,2-dimethylcyclopentane.

Achiral

A molecule that is superimposable on its mirror image, such as compound A (2R, 3S-2,3-dibromopentane) which contains a plane of symmetry.

Polar Protic Solvent

A solvent containing hydrogen bonded to $F, O, \text{ or } N$ (enabling hydrogen bonding) that favors $SN_1$ reactions, such as ethanol or acetic acid.

Polar Aprotic Solvent

A solvent that lacks hydrogen bonding ($H$ not bonded to $F, O, \text{ or } N$) but is polar, such as acetone or $DMSO$, which favors $SN_2$ reactions.

PCC

Pyridinium chlorochromate, a reagent used to oxidize primary alcohols into aldehydes in good yields.

Amide

A functional group characterized by a nitrogen atom bonded to a carbonyl group, represented as $R-NH-C(=O)-R$.

Amine

A functional group consisting of a nitrogen atom bonded to alkyl or aryl groups, represented as $C-N$.

Bond Angle (trigonal planar)

The bond angle of approximately $120^{\circ}$ found in carbon atoms with $sp^2$ hybridization bonded to three groups.

Bond Angle (tetrahedral)

The bond angle of approximately $109^{\circ}$ found in carbon atoms with $sp^3$ hybridization bonded to four groups.

5-ethyl-2-methylheptane

The IUPAC name for the structural formula $(CH_3CH_2)_2CH-CH_2-CH_2-CH(CH_3)_2$.