R-S Convention When referring to a particular enantiomer,we would like to be able to specify which configuration we mean without having to draw the structure,A convention for doing this is know as the R-S convention Rule 1:identify the chiral centres Rule 2:the atoms directly attached to the stereogenic centre are ranked according to atomic number-the higher the atomic number,the higher the priority. CI O C>H Rule 3 if a decision cannot be reached with rule 2,work outwards from the stereogenic centre until a decision is reached.R-S Convention When referring to a particular enantiomer, we would like to be able to specify which configuration we mean without having to draw the structure, A convention for doing this is know as the R-S convention Rule 1 : identify the chiral centres Rule 2 : the atoms directly attached to the stereogenic centre are ranked according to atomic number – the higher the atomic number, the higher the priority. „ Cl > O > C > H Rule 3 : if a decision cannot be reached with rule 2, work outwards from the stereogenic centre until a decision is reached