Ochem toolbox key - Summary Organic Chemistry I PDF

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Attached is a "toolbox" of every organic chemistry reaction that you need to know for organic chemistry 1. I share this with my students now as it seems to be unavailable and it helps them tremendously. ...

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Your Own Personal Organic Chemistry Tool Box

1.

Reactions to know: a. Radical halogenation (heat or hν − various stereocenters produced)

*

Cl

Br

Br2 , hv

Br S

Cl

R

Cl

S

S

b. SN2 bimolecular – inversion CH2OH

CH2OH

NaCN H

Br

NC

H

acetone CH3

CH3

c. SN1 unimolecular (two possible sides to substitute) small amount of E1 possible (elimination – not major product) OCH 3

Cl CH 3OH

minor

major

d. E2, strong bulky base (more substituted is major product) Br NaN(CH3)2

E2

e. Reduction to form alcohol (NaBH4 or LiAlH4) – hydrides (you need protic solvent for NaBH4 but not for LiAlH4 until the workup – 2 steps for LiAlH4) CH(CH3)2

CH(CH3)2

CH(CH3)2 NaBH4

CH(CH3)2 1. LiAlH4, (THF) 2. H+, H2O

CH3CH2OH O

OH reduction

O

or

OH reduction

f.

Oxidation of alcohol (dichromate and water takes 1º alcohols all the way to the carboxylic acid, PCC is organo-soluble and stops at the aldehyde

Na2Cr2O7 H2SO4, H2O HO

O

pyridinium chlorochromate (PCC)

OH

CH2Cl2 O

g. Grignard (attacks ketones/aldehdyes (carbonyl groups) and epoxide rings) – work up protonates the BrMgO-R salt to get the alcohol. (Grignard adds twice to esters and acid chlorides) MgBr

O

1. (CH3CH2)2O

H

H

OH

2. H+, H2O

MgBr H 2O O

1. CH3MgBr O

2. H3

HO

O+

h. Alkyl lithium, e.g. MeLi (same as above) i.

Gilman Reagents (use to make C – C bonds between two halo alkanes Br

1. 2 Li 2. CuI 3.

Br

Prep of alkoxides (K+ -O-R, use really strong base or metal (Na, K reduction) – add alkoxide to alkyl halide (Williamson Ether Synthesis) k. Bromoalkane synthesis from alcohols (primary alcohol SN2, sec or tertiary SN1 subsitution (keep in mind rearrangements or alkyl shifts). j.

OH H-Br

Br H2O

l.

Dehydration of Alcohols to form alkenes (hydride or alkyl shifts possible) using acid with poor nucleophile (H2SO4 or H3PO4) OH H2SO4

m. Haloalkanes from alcohols using PBr3 or SOCl2 (using ether as solvent for PBr3, SOCl2 can be used neat) OH

Cl

SOCl2

OH

Cl

n. Ether syntheses, a little H+ and high temperatures, can also open up epoxides rings (oxacyclopropane rings) below O H 2C

H2SO4 CH2

CH3CH2CH2OH

CH3CH2CH2OCH2CH2OH

o. Dehydrobromination to form alkenes Br NaOCH2CH3 HOCH2CH3

p. Catalytic hydrogenation (syn addition to double bond) watch for stereochem H2/Pt catalyst

q. HBr addition to double bond, electrophilic addition, HBr neat with possibility of rearrangement/hydride shift/alkyl shift (overall Markovnikov) Br

HBr

r.

Add Br2 or Cl2 to a double bond, with H2O around you get the swimming pool reaction, or with ROH you get the alcohol substitution H H3CH2C

H CH2CH3

Br2, CCl4

HR Br

Br

HR

Br HR

R=CH2CH3

HR Br

s.

Mercury acetate cooridinates syn on the double bond, addition is anti, NaBH4 reduces Hg to H. H3CO H

H OCH 3

1. Hg(OAc)2, CH3OH 2. NaBH4, NaOH, H2O

t.

Hydroboration, anti-Markovnikov, peroxide workup, great for 1º alcohols, boron comes as BH3 or B2H6 (diborane - same thing) 1. BH3, THF

OH

2. H2O2, NaOH, H2O

u. Methylene addition to double bonds to form cyclopropane (diazomethane, dichlorocarbene, Simmons-Smith Reagent - below) CH2I2

1. Zn-Cu, (CH3CH2)2O

ZnI2

v. Oxacyclopropane formation: use peroxyacids to form epoxide from double bond, work up with acid/water and get anti addition (dihydroxylation - below) 1. MCPBA, CH2Cl2

OH

HO

HH

HO

H H OH

2. H2O, H+

w. Vicinal Syn-hydroxylation with Osmium tetroxide – exactly what it says 1. OsO4, THF, 25 C 2. H2S

OH

HO HH

OH

HO

HH

x. Ozonolysis Reaction of Alkenes – “nifty” way to open up a ring that has an alkene 1. O3, CH2Cl2 2. (CH3)2S

O

O

y. Radical Additions to alkenes with HBr only: Anti-Markovnikov, needs a peroxide to get things going, aka, generate Br radical (Dr. Walter prefers benzoyl peroxide). Br

HBr (C6H5CO2)2

z. Reactions of Terminal Alkynyl Anions: alkynyl anions can react with ketones, epoxides, aldehydes and haloakanes OH

1. CH3CH2CH2Li, THF 2. epoxide 3. H2O

O

aa. Dissolving Metal Reduction: (in liquid NH3, solvated e- gives trans alkenes exclusively). Na, NH3

bb. Lindlar’s Catalyst: (less active form Pd) only cis alkene product H2, Lindlar's catalyst Pd on CaCO3

cc. HgSO4 addition to alkyne and keto-enol tautomerism product HgSO4

H

H2SO4 HO

H

O

H H H

dd. Hydroboration – Oxidation of alkyne and keto-enol tautomerism just like above, but –OH adds to less substituted side of the triple (anti-Markovnikov) product 1. (Sia)2BH

H

2. H2O2, NaOH H

OH

H H H

O...