-
Hemiketals are
regarded as
hemiacetals where none of the R-groups are H, and are
therefore a
subclass of the
hemiacetals. The Gr****
prefix hèmi means...
- favoured,
hemiacetals in
aqueous solution are in
equilibrium with
their open-chain forms. In
aldohexoses this
equilibrium is
established as the
hemiacetal bond...
- are even less
stable than
those of aldehydes. However,
cyclic hemiacetals and
hemiacetals bearing electron withdrawing groups are stable. Electron-withdrawing...
- form a
hemiacetal.
Under acidic conditions, the
hemiacetal and the
alcohol can
further react to form an
acetal and water.
Simple hemiacetals are usually...
- with C–O–C
linkages are not
considered ethers:
Esters (R–C(=O)–O–R′),
hemiacetals (R–CH(–OH)–O–R′),
carboxylic acid
anhydrides (RC(=O)–O–C(=O)R′). There...
- the
attached alcohol gives the acetal.
Acetals are
stable compared to
hemiacetals but
their formation is a
reversible equilibrium as with esters. As a...
-
detects the
presence of
aldehyde groups, alpha-hydroxy-ketones, and
hemiacetals,
including those that
occur in
certain ketoses. In example, although...
- one monosaccharide, the
reducing sugar of the pair,
still has a free
hemiacetal unit that can
perform as a
reducing aldehyde group; lactose,
maltose and...
- not be
another carbohydrate. A
glycosidic bond is
formed between the
hemiacetal or
hemiketal group of a
saccharide (or a
molecule derived from a saccharide)...
-
finally reacted with
formaldehyde to make vinylon, a
chain of
acetals and
hemiacetals.
Other locations may use
alternative feedstocks to
synthesize PVOH. Between...
