For any single stereoisomer ( there are two enantiomers ), the straight-chain form and the various closed-ring pyranose and furanose forms can easily and rapidly interconvert when dissolved in water.
12.
In an-configuration furanose, the substituent on the highest numbered chiral carbon is pointed downwards out of the plane, and in a D-configuration furanose, the highest numbered chiral carbon is facing upwards.
13.
In an-configuration furanose, the substituent on the highest numbered chiral carbon is pointed downwards out of the plane, and in a D-configuration furanose, the highest numbered chiral carbon is facing upwards.
14.
If the joining of monomers takes place at such a carbon atom, the free hydroxy group of the pyranose or furanose form is exchanged with an OH-side-chain of another sugar, yielding a full acetal.
15.
Both the furanose and pyranose thiosugars can be prepared from the same thiyl radical precursor; 5-" exo " and 6-" endo " cyclizations of this precursor form the respective desired compound.
16.
At pH 7, glucose exists in solution in cyclic hemiacetal form as 63.6 % ?-D-glucopyranose and 36.4 % ?-D-glucopyranose, the proportion of linear and furanose form being negligible.
17.
Glucuronic acid, like its precursor glucose, can exist as a linear ( carboxo-) aldohexose ( D-glucose are capable of forming two furanose forms ( ? and ? ) and two pyranose forms ( ? and ? ).
18.
:Ring closure in sugars is a type of hemiacetal or hemiketal reaction, see also Furanose which is the 5-membered ring of which you speak .-- 32 " "'18 : 28, 6 November 2009 ( UTC)
19.
:Insects-at least some of them-have pyranose receptors and furanose receptors; so anything that elicits response from either one will presumably taste to the insect as a corresponding type of sugar .-- talk ) 06 : 39, 31 July 2009 ( UTC)
20.
In these abbreviated forms, the names of the monosaccharide units are shortened to their corresponding three-letter abbreviations, followed by " p " for pyranose or " f " for furanose ring structures, with the abbreviated aglyconic alcohol placed at the end of the name.
