followed by hydrolysis and decarboxylation.
Gas chromatography  (GC)—A  type    of  chromatography  used    to  separate    vaporizable compounds;
the stationary  phase   is  a   crushed metal   or  polymer,    and the mobile  phase   is  a   nonreactive gas.
Gauche  conformation—A  type    of  staggered   conformation    in  which   the two largest groups  are 60°
apart.
Geminal diol—A  functional  group   with    two hydroxyl    groups  on  the same    carbon; also    called  a
hydrate.
Hemiacetal—A    functional  group   that    contains    a   carbon  atom    bonded  to  one –OR group,  one –OH
group,  an  alkyl   chain,  and a   hydrogen    atom.
Hemiketal—A functional  group   that    contains    a   carbon  atom    bonded  to  one –OR group,  one –OH
group,  and two alkyl   chains.
Heterolysis—Cleavage of a bond in which both electrons are given to the same atom.
High-performance    liquid  chromatography (HPLC)—A form    of  chromatography  in  which   a   small
sample  is  put into    a   column  that    can be  manipulated with    sophisticated   solvent gradients   to  allow
very    refined separation  and characterization;   formerly    called  high-pressure   liquid  chromatography.
Highest occupied    molecular   orbital (HOMO)—The  highest-energy  molecular   orbital containing
electrons;  in  UV  spectroscopy,   electrons   are excited from    the HOMO    to  the LUMO.
Hydride reagent—Reducing reagents containing hydride anions (H–).
Hydrogen    bonding—An  intermolecular  force   that    results from    the extreme polarity    of  the bonds
when    hydrogen    atoms   are attached    to  highly  electronegative atoms   (N, O,  or  F).
Hydrolysis—The breaking of a molecule using water.
Hydroxyl    group—An    –OH group;  seen    in  alcohols,   hemiacetals and hemiketals, carboxylic  acids,
water,  and other   compounds.
