environment.
Enol—The resonance form of a carbonyl that has a carbon–carbon double bond (ene) and an
alcohol (–ol).
Equatorial—Describes groups on a cyclic molecule that are in the plane of the molecule.
Ester—A functional group containing a carbonyl and an alkoxy group (RCOOR).
Extraction—The transfer of a dissolved compound from a starting solvent into a solvent in which
the product is more soluble.
Fingerprint region—In an IR spectrum, the region of 1500 to 400 cm–1 where more complex
vibration patterns, caused by the motion of the molecule as a whole, can be seen; it is characteristic
of each individual molecule.
Fischer esterification—The formation of an ester from a carboxylic acid and an alcohol in acidic
conditions.
Fischer projection—A system to represent three-dimensional molecules in which horizontal lines
indicate bonds that project out from the plane of the page (wedges) and vertical lines indicate
bonds going into the plane of the page (dashes); points of intersection represent carbon atoms.
Flash column chromatography—A technique that speeds up column chromatography by forcing
the solvent through the column by increasing pressure with a nonreactive gas.
Fractional distillation—A modified form of distillation used to separate two liquids with similar
boiling points (less than 25°C apart); uses a fractionation column, which contains inert materials
onto which the liquids can condense and reflux back into the reaction vial, allowing more refined
separation.
Fraction—A volume of eluted fluid from column chromatography; each fraction contains different
compounds that are collected as they leave the column.
Gabriel (malonic-ester) synthesis—A method of synthesizing amino acids that uses potassium
phthalimide and diethyl bromomalonate followed by an alkyl halide; two substitution reactions are