ORGANIC COMPOUNDS CONTAINING OXYGEN, HALOGEN, OR SULFUR

THERE ARE FOUR FAMILIES OF COMPOUNDS THAT CONTAIN A CARBON ATOM SINGLY BONDED TO A HETEROATOM – OXYGEN, HALOGEN, OR SULFUR.

INTRODUCTION

ALCOHOLS ETHERS

ALKYL HALIDES THIOLS

ARE ORGANIC DERIVATIVES OF H20

FORMED BY REPLACING ONE OR TWO HYDROGENS ON THE OXYGEN BY ALKYL GROUPS, RESPECTIVELY.

ALCOHOLS CONTAIN A HYDROXYL GROUP BONDED TO A CARBON.

ETHERS HAVE TWO ALKYL GROUPS BONDED TO AN OXYGEN ATOM

ALCOHOLS & ETHERS

General Structure/Examples

ALKYL HALIDES CONTAIN A HALOGEN ATOM (X = F, Cl, Br OR I) BONDED TO A CARBON.

THIOLS CONTAIN A SULFHYDRYL GROUP (SH group) BONDED TO A CARBON

A THIOL IS A SULFUR ANALOGUE OF AN ALCOHOL.

ALKYL HALIDES & THIOLS

General Structure/Examples

EXAMPLES

14.1 & 14.2

PROBLEMS

ALCOHOLS CONTAIN A HYDROXYL GROUP BONDED TO A TETRAHEDRAL CARBON ATOM.

ALCOHOLS ARE CLASSIFIED AS PRIMARY (1o), SECONDARY (2o) OR TERTIARY(3o)

STRUCTURE & PROPERTIES OF ALCHOLS

A PRIMARY ALCOHOL HAS AN –OH GROUP ON A CARBON TO 1 CARBON A SECONDARY ALCOHOL HAS AN –OH GROUP ON A CARBON TO 2 CARBON. A TERTIARY ALCOHOL HAS AN –OH GROUP ON A CARBON TO 3 CARBON

EXERCISES

CONTAINS AN OXYGEN ATOM SURROUNDED BY 2 ATOMS AND 2 LP OF ELECTRONS

BENT SHAPE

BOND ANGLE OF 109.5o

CAPABLE OF INTERMOLECULAR HYDROGEN BONDING.

HAVE HIGHER BPs AND MPs THAN HCs OF COMPARABLE SIZE AND SHAPE

ARE SOLUBLE IN ORGANIC SOLVENTS

LOW MW ALCOHOLS (< 6C) ARE SOLUBLE IN WATER.

HIGHER MW ALCOHOLS (>6C) ARE INSOLUBLE IN WATER

PROPERTIES OF ALCOHOLS

EXERCISES

NOMENCLATURE OF ALCOHOLS

NOMENCLATURE OF ALCOHOLS

NOMENCLATURE OF ALCOHOLS

NOMENCLATURE OF ALCOHOLS

PROBLEMS

Preparation of Alcohols

INTERESTING ALCOHOLS

CARBOHYDRATES

Alcohols undergo two useful reactions – DEHYDRATION and OXIDATION.

REACTIONS OF ALCOHOLS

1. DEHYDRATION

DEHYDRATION is an example of a general type of organic rxn called ELIMINATION REACTION

ELIMINATION is a reaction in which elements of the starting materials are “LOST” and a new multiple bond is formed.

Example 1

Example 2

named after Alexander Mikhailovich Zaitsev (number of different spellings due to the name being transliterated from Russian) is a rule that states that if more than one alkene can be formed during dehalogenation by an elimination reaction, the more stable alkene is the major product. In general, the compound that has a more highly substituted C=C double bond is more stable.

Zaitsev's rule, Saytzeff's rule or Saytsev's rule

Sample Problem

PROBLEMS

Oxidation occurs by replacing C – H bonds on the carbon bearing the OH group by C – O bonds.

All oxidation products from the alcohol starting material contain a C = O, a carbonyl group

A common reagent for alcohol oxidation is potassium dichromate, K2Cr2O7, a red-orange solid.

2. OXIDATION OXIDATION results in an increase in the number of C – O bonds or decrease in the number of C – H bonds.

Example

Example Primary (1o) alcohols are first oxidized to aldehydes (RCHO), which are further oxidized to carboxylic acids (RCOOH) by

replacing one and then two C – H bonds by C – O bonds.

Example Secondary (2o) alcohols are oxidized to ketones (R2CO), by

replacing one C – H bond by one C – O bond.

Example Tertiary (3o) alcohols have no H atoms on the carbon

with the –OH group, so they are not oxidized.

PROBLEMS

ALCOHOL & THE HUMAN BODY

ETHANOL, THE MOST WIDELY ABUSED DRUG

The products of the biological oxidation of ethanol: