Organic Chemistry I The study of carbon-containing compounds

Unit 1 A little bit of everything…

Oops!  We are not starting at the beginning of Chapter 1… because you need a little more time with the concepts from the following sections: 2.12, 1.10, 1.11, 2.13, 2.14

Hydrocarbons  Compounds that contain only H and C atoms. alkanes (contain all single bonds) alkenes (contain C=C) alkynes (contain C ≡ C) aromatics (contain a benzene ring)

Alkanes  Each C atom is bonded to 4 other atoms...why? methane CH 4 ethane CH 3 CH 3 propane CH 3 CH 2 CH 3 butane CH 3 (CH 2 ) 2 CH 3 pentane CH 3 (CH 2 ) 3 CH 3 hexane CH 3 (CH 2 ) 4 CH 3 heptane CH 3 (CH 2 ) 5 CH 3 octane CH 3 (CH 2 ) 6 CH 3 nonane CH 3 (CH 2 ) 7 CH 3 decane CH 3 (CH 2 ) 8 CH 3

Alkanes  The most significant reaction of alkanes is combustion. This is because alkanes do not have any functional groups.  Functional groups are where reactions occur. CH 3 (CH 2 ) 8 CH O 2 (g)  10CO 2 (g) + 11H 2 O(l)

Showing the Structure of an Organic Molecule  You must be able to read and interpret drawings of molecules from the start!  structural formula = Lewis structure  condensed (structural) formula  line-angle formula  3-dimensional formula  (The molecular formula does not show structure. It just gives numbers and types of atoms.)

Molecular Formula, Lewis Structure, and Condensed Structural Formula These are all the same compound: cis-hex-3-en-2-one The Lewis structure shows all bonds and unbonded valence electrons. Please view the Lewis structures PowerPoint on the 2114 web page if you need a refresher.

Condensed Structural Formula The atoms following the C are bonded to the C: CHCl 2 CH 3 Sometimes the atoms bonded to the leading C are shown on the left: H 3 CCH 2 CH 3 or CH 3 CH 2 CH 3 The C is bonded to the C immediately before it and the C atom immediately after it…all C atoms in molecules have 4 bonds.

Condensed Structural Formula A group bonded to a C is shown in parentheses, except on the last C. Typically, C=C and C ≡ C are shown, but C=O is not. CH 3 CH 2 CH=CHCOCH 3 CH 3 CH 2 CH 2 OH is 1-propanol CH 3 CH(OH)CH 3 is 2-propanol

Line-Angle Structure There is a C at the end of every line segment and enough H atoms to give each neutral C four bonds.

3-D Structure  Solid lines are bonds in the plane of the board or paper.  Wedges show bonds to atoms in front of the plane.  Dashed lines show bonds to atoms behind the plane.

Showing the Structure of an Organic Molecule  START NOW practicing drawing these different types of structures!

Functional Groups Is this compound an alkane? Is it a hydrocarbon? It contains two functional groups: an alkene and a ketone.  Functional groups are sites of reactivity in an organic compound.

Functional Groups  In hydrocarbons alkanes (no functional groups) alkenes (contain C=C) alkynes (contain C ≡ C) aromatics (contain an aromatic ring, the most common of which is the benzene ring) Two representations of a benzene ring…it is NOT classified as an alkene!

Functional Groups  In hydrocarbons

Alkyl Substituents  We look for the longest chain of C atoms in the molecule.  Groups of atoms attached to the C atoms in the chain are called substituents.

Alkyl Substituents  When the substituent is an alkane, it is called an alkyl group.  The letter R is often used to denote an alkyl substituent. a methyl group any alkyl group

Functional Groups  In compounds containing O alcohols (R-OH) ethers (R-O-R’) ketones (contain C=O) aldehydes (contain HC=O) carboxylic acids (COOH) carboxylic acid derivatives  esters (RCOOR’)  amides (RCONH 2, RCONHR’, RCONR’R”)  acid chlorides (RCOCl)

Functional Groups  In compounds containing N amines (RNH 2, RNHR’, RNR’R”) amides (RCONH 2, RCONHR’, RCONR’R”) nitriles (R-C ≡ N)  In compounds containing X alkyl halides or haloalkanes  X=halogen

Functional Groups-Alcohols (R- OH) and Ethers (R-O-R’)

Functional Groups-Aldehydes (HC=O) and Ketones (RC=OR’)  C=O is a carbonyl group.  C=O on the end of the carbon chain is an aldehyde.  C=O elswhere in the carbon chain is a ketone.

Functional Groups-Carboxylic Acids and Their Derivatives  COOH is a carboxylic acid group.  COOR is an ester.  COCl is an acid chloride.

Functional Groups-Amines, Amides, and Nitriles  Amides are like amines, but with an adjacent C=O.  Be careful! Both amines and amides have different forms: primary (1°), secondary (2°), and tertiary (3°).  Nitriles are R-CN.

Primary (1°) Amines and Amides  A primary (1°) amine has one C atom (one alkyl group R) and two H atoms bonded to the N. The general formula is RNH 2.  A 1° amide has one acyl group and two H atoms bonded to the N. The general formula is RCONH 2.

Secondary (2°) Amines and Amides  A secondary (2°) amine has two C atoms (two alkyl groups) and one H atom bonded to the N. The general formula is RNHR’.  A 2° amide has two C atoms (one in the acyl group) and one H atom bonded to the N. The general formula is RCONHR’.

Tertiary (3°) Amines and Amides  A tertiary (3°) amine has three C atoms (three alkyl groups) and no H atoms bonded to the N. The general formula is RNR’R”.  A 3° amide has three C atoms (one in the acyl group) and no H atoms bonded to the N. The general formula is RCONR’R”.

1°, 2°, 3° Amines and Amides  Classify these.

Functional Groups - Alkyl Halides Cycloalkanes are alkanes that have a ring of C atoms. Classify the halides as 1°, 2°, or 3°.

Functional Groups Circle and label each functional group. fructose acetaminophen threonine γ-butyrolactone (GBL) vitamin A (retinol)