Chapter 14: Some compounds with oxygen, sulfur or a halogen

• Alcohol is a compound that has an ¬OH group bonded to a saturated, carbon atom, R¬OH.

• Phenol is a compound that has an ¬OH group bonded directly to an aromatic, benzene-like ring, Ar¬OH.

• Ether is a compound that has an oxygen atom bonded to two organic groups, R¬O¬R.

• Steps to name an alcohol:

  • STEP 1: Name the parent compound.
  • Find the longest chain that has the hydroxyl substituent attached, and name the chain by replacing the -e ending of the corresponding alkane with -ol.
  • STEP 2: Number the carbon atoms in the main chain.
  • The carbon bearing the ¬OH must be assigned the lowest index number possible when numbering the chain.
  • Begin at the end nearer the hydroxyl group, ignoring the location of other substituents for now.
  • In a cyclic alcohol, begin with the carbon that bears the ¬OH group and proceed in a direction that gives the other substituents the lowest possible numbers.
  • STEP 3: Write the name, placing the number that locates the hydroxyl group immediately before the “ol” ending of the alcohol name.
  • Number all other substituents according to their positions, and list them alphabetically.
  • Note that in a cyclic alcohol, it is not necessary to use the number 1 to specify the location of the ¬OH group.

• When the two ¬OH groups are on adjacent carbons (commonly called vicinal diols), diols are often referred to by the common name glycols.

  • Strictly speaking, any diol having the ¬OH groups on adjacent carbons can be called a glycol, but the term “glycol” is preferably reserved for two compounds, ethylene glycol and propylene glycol. Ethylene glycol is the simplest glycol.

• Alcohols with one substituent are said to be primary (1°), those with two substituents are secondary (2°), and those with three substituents are tertiary (3°).

• Alcohols undergo loss of water (dehydration) upon treatment with a strong acid catalyst; the reaction is typically driven to completion by heating. The ¬OH group is lost from one carbon and an ¬H is lost from an adjacent carbon to yield an alkene product and water.

• An organic oxidation is one that increases the number of C¬O bonds and or decreases the number of C¬H bonds.

• An organic reduction is one that decreases the number of C¬O bonds and or increases the number of C¬H bonds.

• Alkoxide ion is the anion resulting from the removal of the H from an alcohol, RO-.

• Thiols (R¬SH), also called thioalcohols or mercaptans, are sulfur analogs of alcohols (an analog is a molecule that has a structure very similar to that of another one in all but one or two key aspects).

• Thiols react with mild oxidizing agents, such as Br2 in water or even O2, to yield disulfides, RS¬SR. Two thiols join together in this reaction, the hydrogen from each is lost, and a bond forms between the two sulfurs.

• Alkyl halide is a compound that has an alkyl group bonded to a halogen atom, R¬X.

• Aryl halide A compound that has an aromatic group bonded to a halogen atom, Ar¬X.

• Stereochemistry is the study of molecules that have the same overall connectivity of atoms but differ in how those atoms are arranged in three-dimensional space.

• Isomers that have the same formula and whose atoms have the same connections but different spatial arrangements are known as stereoisomers.

• Configurations :Stereoisomers that cannot be converted into one another by rotation around a single bond.

• Chirality is having right- or left handedness with two different mirror image forms.

• Achiral is the opposite of chiral, having superimposable mirror images and thus no right- or left-handedness.

• A carbon atom that is BOTH tetrahedral AND has four different groups attached is referred to as a chiral carbon atom, or a chiral center (or stereocenter).

• Enantiomers (optical isomers) is the two mirror-image forms of a chiral molecule.

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