Mari Do Now: – Take out HW – Any questions on the handout from yesterday? Agenda: – Alkenes and Alkynes – Ethers, Ketones, Esters HW: – #4-9,30,31,38-41

IUPAC rules 1. Find the longest straight chain = parent chain 2. Number the parent chain in the direction that gives the lowest number to the substituents at the first point of difference. 3. Two or more identical groups are indicated by di, tri, tetra, etc. Longest chain is 7 (not 6). This is 3-methylheptane.. 2,3,6-trimethylheptane (not 2,5,6-trimethyl heptane) 2,2,6,6,7-pentamethyloctane (not 2,3,3,7,7-pentamethyloctane)

4. Different groups are listed in alphabetical order (di, tri, tetra, etc. don ’ t count; n, sec, tert don ’ t count; iso does). 5. If the numbering is the same in both directions, choose the numbering to follow the alphabetical order. IUPAC rules 6-ethyl-5-isopropyl-2,2-dimethyloctane 5-ethyl-6-methyldecane

cyclic molecules

Nomenclature for Cyclic Alkanes For compounds with a single ring, add the prefix “ cyclo- ” to the root name for the alkane comprising the ring.

Nomenclature of the Substituted Cycloalkanes If there is only one substituent, do not use the “ 1 ”. If there is more than one substituent, you must use all numbers, including “ 1 ” Number around the ring in a direction to get from the first substituent to the second substituent by the shorter path. For equivalent degrees of substitution, number in a direction that follows the alphabetical sequence. A carbon with greater substitution has precedence in numbering.

2. Ethers In an ether, an oxygen atom is bonded to two carbon atoms. –C–O–C–. has a common name that gives the alkyl names of the attached groups followed by ether. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings 7 Diethyl ether

anesthetic perfume solvent industrial solvent

Ether Practice R-O_R Draw the condensed structural formula of methoxy propane:

4. Ketones In a ketone, the carbon of the carbonyl group is attached to two other carbon atoms. Copyright © 2005 by Pearson Education, Inc. Publishing as Benjamin Cummings 10 Acetone

Chapter IUPAC Names for Ketones Replace -e with -one. Indicate the position of the carbonyl with a number. Number the chain so that carbonyl carbon has the lowest number. For cyclic ketones the carbonyl carbon is assigned the number 1. =>

Chapter Examples 3-methyl-2-butanone 3-bromocyclohexanone 4-hydroxy-3-methyl-2-butanone =>

Chapter Boiling Points More polar, so higher boiling point than comparable alkane or ether. Cannot H-bond to each other, so lower boiling point than comparable alcohol. =>

Chapter Solubility Good solvent for alcohols. Lone pair of electrons on oxygen of carbonyl can accept a hydrogen bond from O-H or N-H. Acetone and acetaldehyde are miscible in water. =>

Ketones Practice R-C-R Draw the condensed structural formula for 3-pentanone

14 | 16 Esters Ester – a compound that has the following general formula RCOOR ’ In the general formula for an ester the R and R ’ can be any alkyl group. Although R and R ’ can be identical, they are usually different. Most esters have pleasant odors. Many flowers and ripe fruits have fragrances and tastes due to one or more esters. Section 14.4

Naming Named after alcohol & carboxylic acid from which they are derived. Names of esters end in –oate. CH 3 C CH 2 O O CH 3 ethylethanoate this part from the acid and is named after it this part comes from the alcohol & is named after it let’s name some esters!

Structural formulae Although the previous structural formula are the clearest way of showing esters, they can draw out in a shortened form. ethylethanoate CH 3 C CH 2 O O CH 3 Either… Or… CH 3 C CH 2 O O CH 3 In this version the acid part has been written first Identify the group attached to the C=O – this is from the acid The group attached to the –O- is from the alcohol.

Esters Practice R-O-C-R  Draw the condensed structure for butyl hexanoate

Wait! What’s that smell?  Esters have strong, sweet smells.  Their bouquet is often floral or fruity.  This means they are used in food flavourings & perfumes.  Also, very good at dissolving organic compounds so often used as solvents. esterfragrance ethyl methanoateraspberries 3-methylbutyl ethanoatepears ethyl 2-methylbutanoateapples phenylmethyl ethanoatejasmine