Organic Chemistry I: Chapter 13 PDF

Preview

Summary

Lecture notes for Organic Chemistry II
How to use:
Best for exams. Let’s be honest, exams rarely stray from lecture content. Be sure to memorize everything on the slides. You never know what information is going to pop out. All spoken lecture content is also included as written n...

Description

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Chapter Ten

Structure and Synthesis of Alcohols

Section 10.1 

Alcohol – a compound in which a hydrogen atom of a hydrocarbon has been replaced by a hydroxyl group (-OH).

1

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-3 Nomenclature of Alcohols - Find the longest carbon chain containing the carbon atom bearing the -OH group. - Drop the -e from the alkane name and add -ol to the root name. - Number the carbon chain giving the -OH group the lowest possible number. - Number and name all substituents and place them in alphabetical order.

Section 10-3: Nomenclature

2

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-3: Nomenclature

Section 10-3 

Diols – an organic compound that contains two alcohol (-OH) groups. 

Glycols

Section 10-3 

Phenol – an organic compound with a hydroxyl group bonded directly to an aromatic ring.

3

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-4 Boiling Points - The boiling point of alcohols are higher than similar molecular mass compounds due to hydrogen bonding.

Section 10-4 Solubility - The solubility for the shorter alcohols are very similar to that of water due to the hydroxyl group.

4

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-5 Methanol - Wood alcohol - Industrial production from synthesis gases - Industrial solvent - Toxic Dose: 100 mL

Section 10-5 Ethanol - Grain alcohol - Production from fermentation and ethylene - Industrial solvent - Distillation can produce 95% ethanol - Denatured alcohol is ethanol with impurities such as methanol and methyl isobutyl ketone - Toxic Dose: 200 mL

5

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-5 2-Propanol - Rubbing alcohol - Does not diffuse through the skin - Production from propylene - Toxic Dose: 100 mL

Section 10-6 Acidity of Alcohols - Acidity decreases as the number of carbons increase. - Halogens and other electron withdrawing groups increase acidity.

6

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-6 Formation of Alkoxide Ions - Ethanol reacts with sodium metal to form sodium ethoxide, NaOCH2CH3. - Hindered alcohols like 2-propanol or tert-butanol react faster with potassium than with sodium. - Sodium hydride is a stronger base than both sodium and potassium.

Section 10-6 Acidity of Phenols - Phenol is 100 million times more acidic than cyclohexanol.

Section 10-6 Charge Delocalization

7

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-7 Synthesis of Alcohols - Nucleophilic Substitution on an Alkyl Halide - Synthesis of Alcohols from Alkenes * Acid-Catalyzed Hydration * Oxymercuration-demercuration * Hydroboration-oxidation * Hydroxylation * Addition of Acetylides to Carbonyl Compounds

Section 10-8

Here! ! We’ve been synthesizing alcohols since ch. 6. ! ! By the way we also made an alcohol.! ! Now we focus on the product: alcohol ! !

New stuff!

Organometallic Reagents - Carbon is negatively charged so it will bond to metal like Mg and Li. - Good for forming carbon-carbon bonds.

Section 10-8 

Grignard Reagent – an organomagnesium halide, written in the form R-Mg-X. 



Ethers are used as solvents to stabilize the complex. Reactivity R-I > R-Br > R-Cl >> R-F.

Magnesium AND ETHER — mg v sensitive to water —> mg and water catch fire break down Grignard reagent.

8

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

V. Versatile

Section 10-8 

Organolithium Reagent – an organometallic reagent written in the form R-Li.  

Ether is not required. A wide variety of solvents can be used.

Even more versatile. Don’t need to use ethene. ! ! 2Li instead of Mg.

SAME ARROWS for both ! Section 10-8

9

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Two options for cC bonds.

Section 10-9 Addition of Organometallic Reagents to Carbonyl Compounds

Formed alcohol and C-C bond!

Work backwards. Want primary alco LISTEN!

Section 10-9 Formation of a Primary Alcohol

End goal is primary alcohol.

10

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-9 Formation of a Secondary Alcohol

End goal secondary alcohol

Section 10-9 Formation of a Tertiary Alcohol

Section 10-9 Addition to Acid Chlorides and Esters

Stabilize neg. o2 by forming catbonele

11

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-9 Addition to Acid Chlorides and Esters

Section 10-9 Addition to Acid Chlorides and Esters

Grin in acid chloride and esters. Two R groups added!

Section 10-9 Addition to Ethylene Oxide

Oxygen is takin

12

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-10 Side Reactions of Organometallic Reagents - Grignards are good nucleophiles but in the presence of acidic protons it will act as a strong base. - Will react with water or other acidic protons like OH, NH, S H, or terminal alkynes.

What With any of these, griniyard will normwork m

Section 10-10 Side Reactions of Organometallic Reagents - Will react with electrophilic multiple bonds like C=N, C{ {N, S=O, or N=O.

While drive it seeknoutbel ectropihiic

Section 10-11 Reduction of the Carbonyl Group - Sodium borohydride, NaBH4 - Lithium aluminum hydride, LiAlH4 - Raney nickel

Adding a uniting O2?! !

13

! ! ! ! ! ! Section 10-11 ! ! ! ! ! ! ! ! ! ! ! ! ! ! Section 10-11 Weaker ! reducing ! Sodium Borohydride, NaBH4 agent - Only reacts with carbonyls of aldehydes or ketones, ! not with carbonyls of esters or carboxylic acids. ! ! ! ! ! ! ! ! ! ! KETNEN BECOMES AN help! Section 10-11 ! Lithium Aluminum Hydride, LiAlH4 ! - Stronger reducing agent than sodium borohydride. ! - Reduces ketones, aldehydes, esters, and carboxylic ! acids into the corresponding alcohol. ! ! ! ! ! ! ! ! !

6/30/2017

Increase

Where you usually get CC binds Riki

14

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-11 Raney Nickel - A hydrogen rich nickel powder that is more reactive than Pd or Pt catalysts. - Will reduce double and triple bonds within the molecule.

Just call it a Raney Nickel

15

! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

6/30/2017

Section 10-11 Raney Nickel vs. Sodium Borohydride

Walkin g around  Thiol – the sulfur analogue of an alcohol, R-S-H. knowle Thiols are more acidic than oxygen due to the weaker SH bond. dge Section 10-12



 



Mercaptans Skunk scent is mostly 3-methylbutane-1-thiol and 2butene-1-thiol. Ethanethiol is the odor in natural gas.

Add or suiders hydhns urenury r6

ENo naming or parka of thiols for exam. Walkin g around knowle dge. Ehe 16

! ! ! ! ! ! ! ! ! ! ! ! E! ! ! Dr

6/30/2017

Section 10-12 Reactions of Thiol - SN2 reactions can be used to make thiols.

Section 10-12 Reactions of Thiol

17...