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Review of quiz.

UPAC

1-1 correspondence to a structure and the name

Chemical Abstract (CA)

• system for naming (similar to UPAC) organic chemicals

Steps for naming

1. divide up structure into parent chain and various constituents
2. locant is the carbon atom to which the substituent is attached
3. parent root refers to the # C's
4. suffix refers to the functional group of chain

• -ane
• -ene
• -yne

1. in front, you list substituents

• alphabetical order
• di,tri,tera
• locant for each substituent type

1. eg 3 methyl-5,5-diethyl [parent root # C's] suffix of functional group

• carbon #3 has methyl; #5 has 2 (di) ethyl [parent] + suffix

1. for example

• 1 longest chain of 6
• number from both directions
• the first substituent that has the lowest number determines the direction named
• determine which substituents & their locants
• -ane because
• hex because 6
• dimethyl because 2 methyl
• so it is 2,4-dimethylhexane

1. alphabetical orders (these are all substituents responsible for, in alpab. Order)

• n-butyl
• s-butyl
• t-butyl
• ethyl
• isobutyl
• isopropyl
• methyl
• propyl

1. We are not responsible for complex substituents
2. Nor pentyl substituents
3. Maximize the number of substituents.
4. 
   

Two types of quiz questions:

1. given name, write struture
2. given structure, write name

cycloalkanes

• C3H6 is cyclopropane
• also C4,5,6…30!
• bicyclobutane is double cyclopropanes hooked together
• isopropylcyclohexane
• 1-t-butyl-3-isopropylcyclohexane
• due to the orientation of the ring, isomers can be formed either up or down. This leads to geometric isomers; if they are on opposite sides they are trans (eg trans-1-t-butyl-3-isopropylcyclohexane); if they are on the same side they are cis (eg cis-1-t-butyl-3-isopropylcyclohexane)
• Haworth Projection (flattened structure).
• trans, trans,trans,trans,trans-1,2,3,4,5,6-hexachlorocyclohexane (note: if there are n substituents then there area n-1 stereochemical designations (cis/trans).
• drew trans,trans,trans,trans,cis,trans-1,2,3,4,5,6,7-heptachlorocycloheptane on the board, and named it. (7 carbon ring).

Occurrence of common names

• eg …bicyclo[2.2.2]octene
• common name is barrelene

Conformational Analysis of Alkanes and Cycloalkanes

Rotation between carbon bonds is possible

conformation = different spin orientation around sigma bond

• model give illusion that free spin; do not-rachet between positions

Visualize conformations using Newman Projection

• This is looking at the end of the molecule; don't see back carbon
• play with it; you can see that when H are close they will be unstable.
• when at 60 degrees it is stable.