Orgo II - Unit 5 - Alcohols, Diols, Thiols

Aldehyde + H2/Metal (Reduction)

Primary Alcohol

Ketone + H2/Metal (Reduction)

Secondary Alcohol

Aldehyde + NaBH4 +water/methanol/ethanol (Reduction)

Primary Alcohol

Ketone + NaBH4 +water/methanol/ethanol (Reduction)

Secondary Alcohol

Use NaBD4 in aldehyde/ketone reduction instead of NaBH4

• same concept

• add D onto OH carbon instead of H (when breaking double bond)

Aldehyde + LiAlH4 +diethyl ether + H2O (Reduction)

Primary Alcohol

Ketone + LiAlH4 +diethyl ether + H2O (Reduction)

Secondary Alcohol

Carboxylic Acid + LiAlH4 +diethyl ether + H2O (Reduction)

Primary Alcohol

RMgX + Epoxide + diethyl ether + H3O

Primary Alcohol

Epoxide to Alcohol

• Least crowded C attacked (pri preferred)

Dial

• two aldehydes present

Dial + H2 + Ni

• Forms diol

• OH group at each aldehyde

Alkene + [OsO4 + (CH3)3COOH + OH + tert-butyl alcohol]

• Vicinal Diol

• Syn addition (OH groups are either both dashes or both wedges)

Only —— alcohols can be converted to ethers. Why?

• Primary!

• Secondary/Tertiary alcohols would undergo elimination

Primary Alcohol + H+/heat (or H2SO4/heat)

Ether

Diol + H2SO4/heat

Cyclic ether

Alcohol + Carboxylic Acid (+ H2SO4 for acidic conditions)

Ester

Alcohol + Acid Anhydride

Ester + COOH

Primary Alcohol + Cr2O7 + H2SO4 + H2O (Strong Ox Agent)

Carboxylic Acid

Primary Alcohol + PCC/PDC + CH2Cl2 (Weak Ox Agent)

Aldehyde

Alcohol + Chromic Acid

Alkyl hydrogen chromate

Alkyl hydrogen chromate + Water

Aldehyde or Ketone

Diol + Periodic Acid (HIO4)

Aldehyde or Ketone

Thiols

• Contain SH group

• Bad odor

• very acidic (more acidic than alcohols)

Oxidation of Thiols

• Sulfoxides produced

• Sulfur is a nucleophile with oxygen

Oxidation of Thiols Order

SH —> SOH —> S(O)OH —> SO2OH