thyl Pentoses_ (C_{6}H_{12}O_{5})

Aldoses--_d_- and _l_-Arabinose Aldoses--Rhamnose
_d_- and _l_-Xylose Fucose
_l_-Ribose Rhodeose
_l_-Lyxose Chinovose

_Hexoses_ (C_{6}H_{12}O_{6})

Mannitol series Dulcitol series
Aldoses--_d_- and _l_-Glucose _d_- and _l_-Galactose
_d_- and _l_-Mannose _d_- and _l_-Talose
_d_- and _l_-Gulose
_d_- and _l_-Idose
_d_-Altrose
_d_-Allose
Ketoses-- _d_-Fructose _d_-Tagatose
_d_-Sorbose

_Heptoses_ _Octoses_ _Nonoses_
(C_{7}H_{14}O_{7}) (C_{8}H_{16}O_{8}) (C_{9}H_{18}O_{9})

Glucoheptose Gluco-octose Glucononose
Mannoheptose Manno-octose Mannononose
Galactoheptose Galacto-octose
Persuelose
Sedoheptose

The hexoses are by far the most important group of monosaccharides. They
are undoubtedly the first products of photosynthesis, and all the other
carbohydrates may be considered to be derived from them by condensation.
Because of their biochemical significance and their immense importance as
the fundamental substances for all plant and animal energy-producing
materials, the following detailed studies of their chemical composition and
molecular configuration are fully warranted.

That all the hexoses contain five alcoholic groups is proved by the
experimental evidence that each one forms a penta-ester, by uniting with
five acid radicals, when treated with mineral or organic acids under proper
conditions. Thus, glucose penta-acetate, penta-nitrate, penta-benzoate,
etc., have all been prepared. The presence of the aldehyde group is proved
by the fact that all aldohexoses have been converted, by gentle oxidation,
into pentaoxy-monobasic acids, and the ketohexoses broken down into shorter
chain compounds by similar gentle oxidations; these reactions being
characteristic of compounds containing an aldehyde and a ketone group
respectively. This experimental evidence establishes the nature of the
characteristic groups in the molecule, in each case.

The molecular configurations illustrated in the following table are those
suggested by Emil Fische