Exam 1 Reagents and Reactions

To prepare an alkoxide ion (O-)

deprotonate an alcohol with a strong base, NaH or Na

Marko addition of OH WITH rearrangements

H2O, H2SO4

Marko addition of OH NO rearrangements

1) Hg(oAc), H2O

2) NaBH4

Anti Marko addition of an OH

1) BH3, THF

2) H2O, NaOH

To reduce an Ester or Carboxylic acid to and Alchohol

LiAlH4 (Strong reducer)

To reduce an Aldehyde or Ketone to an Alchohol

NaBH4 (weak) or LiAlH4 (Strong)

Which solvents fo LAH and NaBH4 prefer?

Polar Protic

Preparation of an Alchohol via Grignard

1) R-MgBr

2) H30+

Protection of an Alchohol

TMSCl, Et3N

DEprotection of an Alchohol

TBAF or H3O+

Subsitute OH for X

HX (X= I, Br, Cl)

SN2 substitution of OH with Br (flips)

1) TsCl, py

2) NaBr

or PBr3

SN2 substitution of OH with Cl (flips)

SOCl2, py

Elimination of Tertiary OH for double bond

H2SO4, Heat

Elimination of secondary OH for double bond (anti-zeitzev)

1) TsCl, py

2) t-BuOK

Oxidize an PRIMARY Alchohol to an ALDEHYDE

PCC or DMP (weak oxidizers)

or

1) DMSO (COCl)2

2) Et3N

Oxidize a PRIMARY alcohol to a CARBOXYLIC ACID

Na2Cr2O7 (strong oxidizer), H2SO4, H2O

oxidize a SECONDARY alcohol to a KETONE

PCC (weak) or Na2Cr2O7 (strong)

TERTIARY alchohols

DO NOT oxidize

Williamson Ether Synthesis

1) NaH

2) R-X

Alkoxymercuration Demercuration (alkene to ether)

1) Hg(OAc)2, R-OH

2) NaBH4

Williamson Ether Synthesis ONLY works with

PRIMARY Akyl halides

Acidic Ceavage of an Ether (yields R-OH and R-X)

Excess HX, Heat

To prepare an Epoxide ring

MCBPA

RCO3H

or

1) Br2, H2O

2) NaOH

NUCLEOPHILIC Epoxide opening

1) Na-OR,CN,SR or RMgBr or LiAlH4

2) H3O+

ACID-CATYLIZED Epoxide opening

HX

or

H2O, H+

or

ROH, H+

In BASIC conditions (H3O+ workup needed)

Nucleophile attacks LESS SUBSITUTED carbon

In ACIDIC conditions (no H3O+ workup)

ALWAYS attack TERTIARY if present

otherwise, attack LESS SUBSITUTED