ALDEHYDES AND KETONES

ALDEHYDES AND KETONES A STUDENT SHOULD BE ABLE TO: 1.

Give the IUPAC name given the structure, and draw the structure given the name, of aldehydes and ketones. Also, draw the structure given any of the following common names: formaldehyde, acetaldehyde, benzaldehyde, acetone, acetophenone.

2.

Predict the relative physical properties (boiling point, solubility) of aldehydes, ketones, and previously studied compounds.

3.

Predict the products of reactions giving rise to aldehydes and ketones given the starting material and reaction conditions. Important reactions include: Oxidation of 1° and 2° alcohols Friedel-Crafts acylation Ozonolysis of alkenes Hydroboration of alkynes Acid-catalyzed hydration of alkynes

4.

Predict the products of the reactions of aldehydes and ketones. Important reactions include: Reactions with Grignard reagents, organolithium reagents, and hydrides (reducing agents such as LiAlH4 and NaBH4) Reactions with water and alcohols (to form hemiacetals, acetals, hemiketals, ketals) Reactions with derivatives of ammonia (to form oximes, semicarbazides, hydrazones, imines, and enamines) Reactions with thiols Reactions with ylides (Plus other reactions in the Wittig reaction sequence) Oxidation (H2CrO4, etc.)

Wolff-Kishner reduction of ketones to alkanes Reduction of aldehydes and ketones to alcohols

5.

Propose syntheses using the reactions of Objectives #3 and #4.

6.

Propose mechanisms of reactions involving nucleophilic attack on the carbonyl carbon.

7.

Predict and interpret spectra and solubility test results.

To best prepare for this module, please work Chapter 20 Skill Builder problems in the textbook.

A STUDENT WHO HAS MASTERED THE OBJECTIVES ON THE PREVIOUS PAGE SHOULD BE ABLE TO SOLVE THE FOLLOWING PROBLEMS AND RELATED ONES: 1.1

Draw each of the following compounds. a) acetaldehyde

1.2

b) acetophenone

c) 2-methylcyclopentanone

Name each of the compounds shown.

O O || a) (CH3)2 CHCH2C-CH3

2.

b)

CH3 CH3

O || c) H-CCH2 CH2 Cl

a) Which of the following compounds has the highest boiling point? b) Which has the lowest boiling point?

O CH3 || | A. CH3CCH3 B. CH3CHCH3 C. CH3CH2CH2CH3 D. CH3CH2CH2OH

3.

Predict the product(s) of each of the following reactions.

OH

a)

c)

CH2 CH3 + H2 CrO4 ---->

Cl +

O || AlCl3 C-Cl ------->

3.

Predict the product(s), continued…

e)

4.

C

H2 SO4 CH + H 2 O -----------> HgSO4

Predict the product(s) of each of the following reactions.

O || H3 O + a) (CH3 )2 CHCH + MgBr -----> ---------> b)

O + CH3 OH

c)

O || CCH3 + NH 2 OH ---->

d)

NHNH 2 +

e) O2 N

NHNH 2 +

O ----> O || CH2 CH ---->

NO2 O || dry HCl f) CH3CCH3 + HOCH2CH2OH ------------>

5.

Propose syntheses of each of the compounds indicated, from the given starting material and any other needed reagents.

a)

O || C-H

from

5.

6.

c)

CH2 CH=CH 2 from

d)

CH2 CH=CHCH 3

e)

NNH— || C-CH3

O || CH2 C-H and (C 6 H5 )3 P from

(C6 H5 )3 P

from

Propose a mechanism for the following reaction.

O || C-OCH2 CH3 + 2 CH 3 MgBr ----->

7.1

OMgBr | C(CH 3 )2 + CH 3 CH2 OMgBr

Propose structures for each of the following compounds: (a)

C9H10O2 IR: 1695 cm-1 1

H NMR spectrum triplet, 1.3 (3H) quartet, 4.1 (2H) doublet, 6.9 (2H) doublet, 7.8 (2H) singlet, 9.9 (1H) (b)

C10H12O IR: 1710 cm-1 1

H NMR spectrum triplet, 1.0 (3H) quartet, 2.2 (2H) singlet, 3.8 (2H) singlet, 7.2 (5H)

SOLUTIONS TO SAMPLE PROBLEMS: 1.1

a) acetaldehyde O | | CH3 C-H

b) acetophenone O || C-CH3

1.2

a) 4-methyl-2-pentanone b) 3,3-dimethylcycloheptanone c) 3-chloropropanal

2.

a) Highest boiling point: D

3.

The reactions give these products:

c) 2-methylcyclopentanone O

b) Lowest boiling point: B

OH

O

a)

c)

e)

CH3

CH2 CH3 + H2 CrO4 ---->

Cl +

C

CH

O || AlCl3 C-Cl ------->

H2 SO4 + H 2 O -----------> HgSO4

CH2 CH3

O || C—

O || C-CH3

Cl

(and ortho)

3.

4.

And these reactions give the products shown here: O || a) (CH3 )2 CHCH +

+ H 3O MgBr -----> --------->

OCH3

b)

O + CH3 OH

c)

O || CCH 3 + NH 2 OH ---->

d)

NHNH 2 +

e) O2 N

OH | (CH 3 )2 CHCH

NHNH 2 +

OH NOH || CCH 3 + H 2 O

O ---->

N—N

| H

O || CH2 CH ---->

NO2

O || f) CH3 CCH3 + HOCH2CH2 OH ---->

O

NNH || CH2 CH NO2

O

CH3 CCH3 + H2O

NO2

5.

Synthesis: a)

Br2 -------> FeBr3

Mg Br -----> ether

H2 C=O H3 O MgBr ----------> O || C-H

c)

P CC <-------

+

CH2 OH

+ (C6 H5 )3 P + CH 3 Br ----> (C6 H5 )3 P-CH 3 + Br+ (C6 H5 )3 P-CH 3 + NH 2 - ----> (C 6 H5 )3 P=CH 2 + NH 3 (C6 H5 )3 P=CH 2 +

O || CH2 C-H ----> (C 6 H5 )3 PO +

CH2 CH=CH 2

+ d) (C6 H5 )3 P + CH 3 CH2 Br ----> (C6 H5 )3 P-CH 2 CH3 + Br (C6 H5 )3 P-CH 2 CH3 + NH 2 - ----> (C6 H5 )3 P=CHCH 3 + NH 3 (C6 H5 )3 P=CHCH 3 +

O || CH2 C-H ---> (C6 H5 )3 PO + CH2 CH=CHCH 3

e)

O || CH3 C-Cl ------------> AlCl3

O || C-CH3

NHNH 2 ----------------------->

NNHâ&#x20AC;&#x201D; || C-CH3

6.

Mechanism:

7.1

Unknowns: a)

CHO

O CH2 CH3

O b)

CH2-C-CH 2CH3

Name __________________________________________________Sixth Drill Test (Sample A) Organic Chemistry 2220DR Answer All Questions 1.

Which of the following compounds has the highest boiling point? Which has the greatest water solubility?

OH O OH O | || | || CH3 CH C-H CH CH 3 C

2.

Name:

3.

Draw the structure of 1,1-diiodo-3-pentanone

4.

Predict the product or products (if any) of each of the following reactions. a)

b)

c)

CH3 OH

H2 SO4 + CrO3 ---------->

NHNH 2

O || + (CH3 )2 CHCH 2 C-H ----->

O || C-H + (CH 3 )2 CHM gBr

H3 O

5.

Propose a synthesis of each of the compounds shown, from the given starting material and any other needed reagents.

Name __________________________________________________Sixth Drill Test (Sample B) Organic Chemistry 2220DR Answer All Questions 1.

Which of the following compounds gives a new product on reaction with H2CrO4, and decolorizes Br2 in CCl4?

O O || || A. H-C-CH=CH 2 B. H-C-CH 2 CH 2 Br

O || C. CH 3 C-CH =CH 2

2.

Give the IUPAC name for the following compound.

O || CH3CHCHC-H | CH3

4.

Predict the product of each of the following reactions.

O || a) CH3CCH2CH3

Draw the structure of 2,3-dimethylcyclopentanone.

CH3CH2CH2Li

O || b) CH3C-H + 2 CH3OH

5.

3.

O || D. CH 3 C-CH 2 CH 2 Br

acid

Propose a synthesis of the compounds indicated from the given starting materials and any other needed reagents. a)

=NNH— NO2

NO 2 from

—OH

b)

6.

CH3 / CH=C from \ CH3

Propose a mechanism for the reaction shown.

CH3 CO2CH3

7.

OH | CH3 CHCH3 and (C6 H5 )3 P

OMgBr | + 2 C 2 H5 MgBr -----> CH3OMgBr + CH3 C(CH 2 CH3 )2

An unknown has the formula C4H6O and a strong peak in the IR spectrum near 1690 cm-1.

The pmr spectrum is: doublet, 2.0, 3H multiplet, 6.1, 1H multiplet, 6.9, 1H doublet, 9.5, 1H Give the structure of this unknown.