ABSTRACT
This chapter outlines the drawing conventions used in the Combined Chemical Dictionary (CCD), which other chemists may wish to follow. The conventions adopted for CCD closely follow the International Union of Pure and Applied Chemistry (IUPAC) recommendations on graphical representation standards for chemical structure diagrams and graphical representation of stereochemical configuration. The Zigzag Natta projection provides a clear and unambiguous representation of a compound. Generally speaking, all carbon and hydrogen atoms are implicit, with the exception of those that form part of a functional group such as a carboxylic acid (COOH) or aldehyde (CHO). For simple aromatic compounds, the ring is orientated such that the 1 position is at the top or top right of the ring and numbered in a clockwise direction, again keeping the general horizontal layout. In CCD, heterocyclic compounds are drawn with the heteroatom towards the bottom or bottom right and numbered anticlockwise. Stereochemical configuration is shown with the use of solid wedge and hashed lines.
