Oxidation of an alcohol: H2SO4,K2Cr2O7 O CH3CH2OH CH3 C alcohol warm H aldehyde further warming O carboxylic acid CH3 C O H

Note: In organic reactions, the side products (e. g Note: In organic reactions, the side products (e.g. Cr3+ in the preceding reaction) are often not given. Here is the complete chemical equation:

Note: In organic reactions, the side products (e. g Note: In organic reactions, the side products (e.g. Cr3+ in the preceding reaction) are often not given. Here is the complete chemical equation: 16 H+ + 2 Cr2O72- + 3 CH3CH2OH 4 Cr3+ +3CH3CO2H + 11 H2O

Note: In organic reactions, the side products (e. g Note: In organic reactions, the side products (e.g. Cr3+ in the preceding reaction) are often not given. Here is the complete chemical equation: 16 H+ + 2 Cr2O72- + 3 CH3CH2OH 4 Cr3+ +3CH3CO2H + 11 H2O (orange) (green)

The intermediate reaction would be: 8 H+ + Cr2O72- + 3 CH3CH2OH 4 Cr3+ + 3 CH3CHO + 7 H2O (orange) (green)

Oxidation of an alcohol: OH H2SO4,K2Cr2O7 O CH3CHCH3 CH3CCH3 alcohol or KMnO4 ketone

Aromatic Compounds

Aromatic Compounds Aromatic – from aroma – a number of these compounds have strong and sometimes pleasant odors.

Aromatic Compounds Aromatic – from aroma – a number of these compounds have strong and sometimes pleasant odors. The most important compound in this family is benzene.

Benzene C6H6 This is a very important example in organic chemistry – an example of resonance: C C C C C C

The two resonance structures are averaged leading to the following structure: C C C

If resonance were not important for benzene, i. e If resonance were not important for benzene, i.e. only one of the two preceding resonance structures were required to describe the structure of benzene, then we might expect benzene to have a reactivity similar to

If resonance were not important for benzene, i. e If resonance were not important for benzene, i.e. only one of the two preceding resonance structures were required to describe the structure of benzene, then we might expect benzene to have a reactivity similar to CH2 CH CH CH CH CH2

If resonance were not important for benzene, i. e If resonance were not important for benzene, i.e. only one of the two preceding resonance structures were required to describe the structure of benzene, then we might expect benzene to have a reactivity similar to CH2 CH CH CH CH CH2 1,3,5-hexatriene

If resonance were not important for benzene, i. e If resonance were not important for benzene, i.e. only one of the two preceding resonance structures were required to describe the structure of benzene, then we might expect benzene to have a reactivity similar to CH2 CH CH CH CH CH2 1,3,5-hexatriene This is not the case!

If resonance were not important for benzene, i. e If resonance were not important for benzene, i.e. only one of the two preceding resonance structures were required to describe the structure of benzene, then we might expect benzene to have a reactivity similar to CH2 CH CH CH CH CH2 1,3,5-hexatriene This is not the case! 1,3,5-hexatriene is fairly reactive with a variety of reagents (e.g. HBr, Cl2, etc. in the dark). These reagents react only slowly with benzene.

Benzene is more stable than might be expected by examination of the individual resonance structures.

Naming benzene compounds

Naming benzene compounds chlorobenzene

1,2-dibromobenzene

1,2-dibromobenzene 1,3-dibromobenzene

1,2-dibromobenzene 1,3-dibromobenzene 1,4-dibromobenzene

o-dibromobenzene m-dibromobenzene p-dibromobenzene

o-dibromobenzene m-dibromobenzene o = ortho m = meta p = para p-dibromobenzene

Steroids

IUPAC name (10R, 13R)-10,13-dimethyl-17-(6-methylheptan-2-yl)-2,3,4,7,8,9,11,12,14,15,16,17-dodecahydro-1H-cyclopenta[a]phenanthren-3-ol

Cortisone

oral contraceptive

Some misc. Molecules

Theobromine (replace the CH3 at the arrow by H) is the stimulant found in

Theobromine (replace the CH3 at the arrow by H) is the stimulant found in chocolate.

Stereochemistry

Stereochemistry Stereochemistry: Deals with the 3-dimensional arrangement of atoms in space for a particular chemical structure.

Stereochemistry Stereochemistry: Deals with the 3-dimensional arrangement of atoms in space for a particular chemical structure. It also deals with how molecules react in 3-dimensions.

Isomers

Isomers Two or more compounds with the same molecular formulas but different arrangements of the atoms in space.

Isomers Two or more compounds with the same molecular formulas but different arrangements of the atoms in space. Three different types of isomerism will be considered.

Isomers Two or more compounds with the same molecular formulas but different arrangements of the atoms in space. Three different types of isomerism will be considered. 1. Structural isomers (constitutional isomers)

Isomers Two or more compounds with the same molecular formulas but different arrangements of the atoms in space. Three different types of isomerism will be considered. 1. Structural isomers (constitutional isomers) 2. Geometric isomers

Isomers Two or more compounds with the same molecular formulas but different arrangements of the atoms in space. Three different types of isomerism will be considered. 1. Structural isomers (constitutional isomers) 2. Geometric isomers 3. Optical isomers

Structural isomers

Structural isomers Structural isomers (constitutional isomers): Compounds with the same molecular formulas but different arrangements of the atoms.

Structural isomers Structural isomers (constitutional isomers): Compounds with the same molecular formulas but different arrangements of the atoms. Example: Draw the structural isomers for C4H10

CH3CH2CH2CH3 butane

CH3CH2CH2CH3 butane CH3CHCH3 2-methylpropane CH3 (the 2 is redundant in this name)

Example: Draw the structural isomers for C5H12

Example: Draw the structural isomers for C5H12 CH3CH2CH2CH2CH3 pentane

Example: Draw the structural isomers for C5H12 CH3CH2CH2CH2CH3 pentane CH3CH2CHCH3 2-methylbutane CH3 (2 is redundant)

Example: Draw the structural isomers for C5H12 CH3CH2CH2CH2CH3 pentane CH3CH2CHCH3 2-methylbutane CH3 (2 is redundant) CH3 CH3CCH3 2,2-dimethylpropane CH3 (each 2 is redundant)

Example: Draw the structural isomers for C2H6O

Example: Draw the structural isomers for C2H6O CH3CH2OH ethanol

Example: Draw the structural isomers for C2H6O CH3CH2OH ethanol CH3OCH3 methoxymethane (dimethyl ether)