Nomenclature for Naming Disaccharides

step 1

type of atom involved in linkage

step 2

configuration of the anomeric hydroxyl of the 1st sugar (alpha or beta)

step 3

name of 1st monosaccharide, root name followed by pyranosyl (6 ring) or furanosyl (5-ring)

step 4

atoms that are linked tgt, 1st sugar then 2nd sugar

step 5

configuration of the anomeric hydroxyl of the second sugar (alpha or beta) (often omitted)

step 6

name of 2nd monosaccharide, root name followed by pyranose (6-ring) or furanose (5-ring)

how to determine which C is anomeric

C that is connected to 2 diff O₂

how to know when a sugar is fructose in ring form?

1) when bonded, the 2nd carbon is linked meaning that C was originally a carbonyl

2) 6 C ring

3) 2 hydroxylmethyl group (CH₂OH)

how to know when a sugar is reducing?

the anomeric C(s) have a free aldehyde (R-CHO), ketone (CH₂O), hemiacetal (R¹HC(OH)OR²), or hemiketal (R²R¹C(OH)OR³)

when is it named -side?

the anomeric C(s) is/are bonded, so no aldehyde, ketone, hemiactel, or hemiketal grp

when is it named -ose?

the anomeric C(s) still have aldehyde, ketone, hemiacetal, or hemiketal grp