organic compounds containing oxygen, halogen, or...
TRANSCRIPT
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: