Orgo unit 1

Alkane (Substituent: alkyl)

• a hydrocarbon with no multiple bonds

• nonpolar

• tetrahedral (sp3 hybridized)

• free radical reactions

Alkene (Substituent: alkenyl)

• a hydrocarbon with at least 1 C-C double bond

• nonpolar

• trigonal planar (sp2 hybridized)

• addition reactions, oxidative cleavage

• stability increases with # carbons attached

Alkyne (Substituent: alkynyl)

• a hydrocarbon with at least 1 C-C triple bond

• nonpolar

• linear (sp hybridized)

• addition reactions, oxidative cleavage, acid-base reactions

Benzene Ring (Substituent: phenyl)

• a 6-membered ring containing 3 alternating double bonds

• substitution reactions (less reactive than normal alkenes bc aromaticity)

Alcohol (Substituent: hydroxy)

• OH group attached to C (unless attached to C=O)

• polar (OH does hydrogen bonding)

• acid-base reactions, substitution reactions, oxidation reactions

ether (Substituent: alkoxy)

• an oxygen flanked by two carbons

• borderline between polar and nonpolar (dipole-dipole)

• acid-base reactions

alkyl halide (Substituent: haloalkyl)

• an alkyl group attached to a halogen

• considered nonpolar but more polar than alkanes

• substitution and elimination reactions

amine (Substituent: amino)

• a nitrogen attached to a simple carbon or hydrogen atoms

• polar (N-H does hydrogen bonding)

• acid-base, substitution reactions

aldehyde (Substituent: oxo)

• a carbonyl (C=O) attached to hydrogen and another carbon

• C=O bond is somewhat polar

• addition reactions

ketone (Substituent: oxo)

• a carbonyl (C=O) flanked by two carbons

• C=O bond is somewhat polar

• addition, acid-base reactions

carboxylic acid (suffix: -oic acid)

• a carbonyl (C=O) adjacent to a hydroxyl (OH) and an R group

• acid-base, acyl substitution reactions

ester

• a carbonyl group adjacent to an alkoxy (OR) and an R group

• acyl substitution reactions and addition reactions

thiol (Substituent: mercapto)

• sulfur-containing analogs of alcohols

• acid-base reactions, substitution reactions

sulfide (suffix: sulfide)

• a sulfur flanked by two carbon atoms

• reduction reactions

epoxide (suffix: oxide)

• cyclic ethers consisting of a 3-membered ring containing 1 oxygen and two carbons

• ring opening when treated with nucleophiles

nitrile (suffix: nitrile)

• a molecule containing the CN group

• reduction reactions, hydrolysis reactions

imine (suffix: imine)

• nitrogen-containing analogues of ketones and aldehydes

• reduction reactions, hydrolysis

acyl halide (suffix: -oyl halide)

• Carboxylic acid derivatives where OH has been replaced by a halogen

• acyl substitution reactions

amide (suffix: amide)

• nitrogen-containing analogues of esters

• reduction reactions, hydrolysis reactions

anhydride (suffix: anhydride)

• oxygen atoms flanked by two acyl groups

• acyl substitution reactions, reduction reactions

Nitro

• a molecule containing the NO2 group

• reduction reactions, acid-base reactions

Enol

• alkenes attached to a hydroxyl substituent

• good nucleophiles, will perform addition reactions to aldehydes and ketones

• also will tautomerize to aldehydes and ketones

Enolate

• the conjugate bases of enols

• excellent nucleophiles

• addition reactions to aldehydes and ketones

• substitution reactions with alkyl halides

Enamine

• alkenes attached to an amino substituent

• excellent nucleophiles

• addition reactions to aldehydes and ketones

• substitution reactions with alkyl halides

tert-butyl

isopropyl

isobutyl

sec-butyl

Formula for Degrees of Unsaturation

A formula used to determine the number of rings and multiple bonds in a molecule. It is calculated as $DU = 1 + n - \frac{m}{2} + \frac{o}{2} - \frac{q}{2}$, where (n) is the number of carbons, (m) is the number of hydrogens, (o) is the number of nitrogens, and (q) is the number of halogens.

Polar Effect

An atom not connected to H draws e- density due to its electronegativity which weakens H and other atom bond —> dissociation —> stronger acid.

Charge Effect

Atom connected to H has + formal charge —> atom less stsable —> easier to remove H —> neutral or stable covalent bond

Element effect

atom connected to H is lower on periodic table —> larger atom —> weaker and longer bond —> easier for H to dissociate. can also argue atom connected to H is more electronegative so greater e- density and weaker bond —> easier for H to dissociate

Neopentyl

Anti conformation - newman projection

lowest staggered confirmation

Gauche conformation

other 2 staggered conformations - not anti

eclipsed - newman projection

steric hinderance, without hyperconjugation

staggered - newman projection

less steric hinderance and hyperconjugation can occur. this hyperconjugation leads to lower energy and thus makes for a more stable conformation

2sp3 hybridization electron energy diagram

4 sigma bonds

how many bonds can sp3 hybridization make

2sp2 hybridization electron energy diagram

3 sigma bonds, 1 pi bond

how many bonds can sp2 hybridization make

HCl pKa

-7 pKa

hydronium pKa

-1.5 pKa

carboxylic acid pKa

~5 pKa

ammonium pKa

~9 pKa

H2O pKa

15.7

ammonia pKa

35 pKa

molecular orbital diagram for pi bond

sigma anti-bonding molecular orbital

pi anti-bonding molecular orbital

stereoisomer

molecules that have the same molecular formula and sequence of bonded atoms (constitution), but differ in the three-dimensional orientations of their atoms in space

constitutional isomer

compounds with the same molecular formula but different bonding arrangements. While they share the exact same number and types of atoms, the atoms are connected in a different order, leading to distinct physical and chemical properties

when does an acid dissociate (explain using pKa values)

if solution pKa is less than acid pKa, the acid will not dissociate. if the solution has a higher pKa than the acid, then the acid will dissociate.

Markovnikovs rule

a more substituted carbocation will form as an intermediate. this is more stable because there are more instances of sigma bonds aligned with empty p orbitals and thus more instances where hyperconjugation is possible

molecular orbital diagram justification for markovnikovs rule