ABSTRACT
Carbohydrate nomenclature has an impact on stereochemistry and on the nomenclature of certain other compounds, which are often named as modified carbohydrates in Chemical Abstracts (CAS) and elsewhere. The stereochemical designation of a fundamental aldose is arrived at by assigning it to the d- or l- series, depending on the absolute configuration of the highest-numbered chiral centre of the chain. Carbohydrates may be represented as Fischer, Haworth or Planar (Mills) diagrams, as well as zigzag diagrams as used for non-carbohydrates. Sugars having more than six carbon atoms are named using two prefixes, one defining the configuration at C-2 to C-5 as in a hexose and the other, which appears first in the name, defining the configuration at the remaining chiral centres. Reduction of the carbonyl group of an aldose gives the series of alditols. Peptides are oligomers notionally derived from amino acids by condensation to produce amide linkages. Steroids are naturally occurring compounds with synthetic analogues based on cyclopenta[a]phenanthrene skeleton.
