Organic Chemistry-Semester 1

question

Acid/Base

 

Electrophile/Nucleophile

 

 

answer

Neutralized Substance (frequently HOH)

 

A + :B AB

question

Sn2

 

Alkane w/ Leaving Group (1°)

 to

Replaced Leaving Group

 

answer

Nucleophile

 

   H                      H              H

C-C-L + :Nu →[ Nu-C-L ] → Nu-C-C + :L

   H                     CH              H 

 

Inversion

question

Sn1

 

Alkane w/ Leaving Group (2/3°)

to

Alkane w/ New Substituent (has E1 by-product)

answer

Nu:

 

   C          C                    C 

C-C-L C-C + + :NuC-C-Nu

   C           C                   C

 

Racemate

question

E2

 

Alkane w/ Leaving Group (1/2°)

to

Alkene

answer

Nu:

 

      H                                  H              H

H-C-C-L + :Nu → [Nu–H–C==C–L] → C=C

      H                                  H              H

question

E1

 

Alkane w/ Leaving Group (3°)

to

Alkene

answer

Nu:

 

      C            C                                     C 

H-C-C-L →  H-C-C+ + :Nu → [ Nu–H–C==C ] →

      C            C                                     C

    C

C=C

    C

question

Dehydrohalogenation

 

Alkyl Halide

to

Alkene

answer

Nu:

 

By E2/1

question

Acid Catalysed Dehydration

 

Alcohol (3º>2º>1º)

to

Alkene

answer

Strong Acid

 

H adds to -OH

 

Proceeds as E1/2

question

Double Elimination

 

Vicinal Dihalide

to

Alkyne

answer

 

Nu: (2eq)

 

2 repeated E2 reactions

question

Rearrangement

 

1º/2º Cation

 

 

answer

3º Cation

 

An entire subsituent moves over to the 1º/2º cation to make more stable

question

Replacement

 

Terminal Alkyne

to

Terminal Alkynide

 

answer

NaNH2, NH3, Li…

 

R-CΞC-H → R-CΞC:

question

Hydrogenation

 

Alkene

to

Alkane

answer

 

H2, Pd/Ni

 

Double bond attacks H in H2

question

Hydrogenation

 

Alkyne

 

Syn Alkene

 

 OR

 

Anti Alkene

answer

Ni2B, H2

OR

Li, EtNH2 (Radical)

 

 

question

Addition

 

Alkene

to

Alkyl Halide

answer

HX

 

Double bond attacks H (adds to side w/ most H’s), creates a Cation, X- attacks.

;

;REARRANGEMENT can happen.

question

Acid Catalysed Hydration

;

Alkene

to

Alcohol

;

answer

1)HA

2) OH

;

Double bond attacks H on Acid, then Conj. Base attacks cation.; OH attacks C with sulfonate.

question

Acid Catalysed Hydration

;

Alkene

to

Alcohol (3;/2;)

;

answer

SA, H2O

;

Double bond attacks H on acid, forms cation.; H2O attacks cation.; Conjugate base deprotonates the O+ formed.

question

Oxymercuration/Demercuration

;

Alkene

to;

Alcohol (no rearrangement)

answer

Hg(COOCH3)2 , THF (becomes Cation), H2O

;

Double bond attacks Hg, forms bond from both C’s.  Hydrogenation occurs. 

NaBH4, OH

H attacks C w/ Hg

 

 

question

Hydroboration

 

Alkene

to

Alkyl Borane

answer

BH3

 

Double bond attacks B, kicks out an H

 

(occurs for each H)

question

Oxidation and Hydrolysis

 

Alkylborane

to

Alcohol

answer

HOO, NaOH

 

Peroxide Ion attacks B, R attacks 1st O, forms ether.  Repeats 3 times.

 

OH attacks B, kicks out O-R, which attacks H on BOROH. 

question

Addition

 

Alkene

to

Vicinal Dihalide

answer

Cl2, CCl4

 

C=C forms ring with a Cl, Cl attacks from other side

 

TRANS

question

Addition

 

Alkene

to

Halohydrin

answer

X2, H2O

 

C=C forms ring with X, H2O goes through Hydration

question

Carbene Formation

 

Diazomethane (:CH2-NΞN:)

to

Carbene

answer

 

N-C bond breaks and

:CH2 forms

question

Cyclopropane formation

 

Alkene

to

Cyclopropane

answer

Carbene

 

Cyclic donation from double bond to carbene and vice versa.

question

Oxidation

 

Alkene

to

Diol (Syn)

answer

1) OsO4, Pyradine 2)NaSO3/H2O

OR

KMnO4, OH, H2O

 

Double Bond attacks an O, an O attacks the other Carbon, and the H’s attack at O bonds.

question

Oxidative Cleavage

;

Alkene (alkyne)

to

Carboxylic Acid, CO2, or Ketone (carboxylic acid)

answer

1) KMnO4, OH, H2O, heat 2)H3O+

;

Breaks double bond, adds a =O.

question

Oxonolysis

;

Alkene

;

1) O3, CH2Cl2 2);Zn, HOAc

answer

Aldehyde/Ketone

;

Forms C-C;Ring

;; O-O-O

Which changes to a C-O-C Ring

;;;;;;;;;;;;;;;;;;;; O; O

Which breaks apart w/ Zn, HOAc

question

Addition

;

Alkyne

to

Dihaloalkene (trans)

Tetrahaloalkane

answer

X2, CCl4

;

Adds 1/2 times depending on eq

(like addition to Alkene).

question

Addition

;

Alkyne

to

Haloalkene

answer

HX (for Markovnikov)

;

HX and ROOR (for Anti-Markovnikov)

;

question

Addition

;

Haloalkene

to

Geminal Dihalide

answer

HX

;

Adds Markovnikov, so adds X to C with other X.

question

Radical

;

Alkane

to

Alkyl Halide

answer

X2, Light

;

Cl; abstracts the H, leaving a radical.; Cl; attacks the radical.

question

Anti-Markovnikovian Addition

;

Alkene

to

Alkyl Halide

answer

HX, light, ROOR

;

RO; abstracts H from HX, X; attacks double bond, the radical C abstract and H from HX.

;

;

question

Substitution

;

Alcohol

to

Alkyl Halide

;

answer

HX, PBr3, SOCl2 and pyradine

;

OH attacks either P or H, making a good leaving group.; X will then attack the C.

question

Intermolecular Dehydration

;

1; Alcohol

to

Ether

answer

HA

;

R-OH ; R-OH2 ; [ROH–R–OH2] → ROR → ROR

                                        H

question

Williamson Synthesis

 

Alcohols

to

Ether

answer

K or NaH and R’-L

 

R-OH → R-ONa/K → R-O-R’ (Na/K+ and L)

question

Alkoxymercuration/Demercuration

 

Alkene

to

Ether

answer

1) Hg(OOCCF3)2, HO-R’

2) NaBH2, OH

 

 

question

Protecting Groups

 

Alcohol

to

Protected Ether

answer

H2SO4, C=C(CH3)2

 OR

ClSi(CH3)2CH3, Imidiazole, DMF

(Bu4NF, THF to remove)

 

Use to get a base to attack a C rather than an H

question

Cleavage

 

Ether

to

Alkyl Halide and Alcohol

answer

H-X

 

H adds to O, stablest cation forms (or X attacks-Mark)

     H 

  R-O-R’ → R-OH + R’+ or R’X

question

Formation of Epoxides

 

Alkene

to

Epoxide

answer

Peroxyacid

 

Forms cyclic bond with OH from ROOH, also forms a carboxylic acid

question

Acid Catalysed Ring Opening

 

Epoxide

to

Akyl ____

answer

Water or other Weak Acid

 

O attacks H from Acid, acid attacks C and OH breaks off to form an Alkyl whatever.

question

Base Catalysed Ring Opening

 

Epoxide

to

Alkyl______

answer

Strong Base and NH4Cl

 

Base attacks the C, O breaks off, attacks a Hydrogen.

question

Reduction by Hydride Transfer

 

Carboxyl Group

to

Alcohol

answer

1) LiAlH4, Et2O 2) H2SO4/H2O

or

BH4, H2O

 

Donates an H, Oattacks an H (or pushes out an OH)

question

Oxidation

 

Alcohol

to

Aldehyde (1°), Carboxylic Acid (1°), or Ketone

answer

PCC, CH2Cl2

or

KMnO4, OH, H2O, heat, H3O+

or

CrO3 (HCrO4, Acetone), H2O (JONES REAGENT)

question

Organometal Formation

 

Alkyl Halide

to

Organometal

answer

Mg or Li (Et2O, THF)

 

Replaces X

question

Acid/Base

 

(What can go WRONG)

 

Carboxyl group with an acidic H

to

Alkane

answer

 

 

Organometallic attacks the H rather than the C with the =O

 

(Works with -OH, and CΞCH notably)

question

Grignard/Lithium Rxn

 

Carboxyl Group

to

Alcohol

answer

Grignard/Organolithium Reagent or C≡C:, H3O+

 

R group on Organometallic attacks C with =O.

 Also works in Epoxides with C-O

 

Esters will act as a leaving group

question

Corey-Posner, Whiteside-House Synthesis

 

Alkyl Halide

to

Dialkyl cuprate

answer

Li in Et2O and CuI

 

Li replaces X, Cu takes place of Li to get CuLi compound with 2 alkyl groups

question

Corey-Posner Whiteside-House Synthesis

(part deux)

 

Alkyl Halide

to

Alkane

answer

Dialkyl Cuprate

 

Alkyl Group takes place of X

question

Allylic Substitution

 

Alkene with ≥1 branch

to

Halo-alkene

answer

X2, Heat

also: NBS, hv, CCl4

 

X· Forms, abstracting an H and leaving a radical on an allylic carbon.  Through RESONANCE, many different placements of the X occur.

question

Diels-Alder Reaction

 

Diene (best if with edonating group)

to

Six-Membered Ring

answer

Alkene with e withdrawing group (Electron Acceptor)

 

Resonance makes the donor/acceptor possible, number carbons along double bonds 1-4 and 5-6 to show bonds of ring.

 

***IN=UP, OUT=DOWN***

 

 

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