Optical Isomers

Date Published

Where a racemic mixture is known for a specific use and the problem is to find a compound having that property in an enhanced level, or the same property with less side-effects, the question inevitably arises whether one of the isomers in isolation is an obvious solution. It is reasonable to presume that it is common general knowledge that one isomer is often more active than the other, although this is not invariably the case. The single isomer will be an obvious solution if it would have been a matter of routine to prepare the single isomer and test its activity.

If the isomer is prepared by routine separation techniques, the single isomer will be an obvious solution. This is true even if it was not obvious beforehand which of the isomers would be more active.

See Rhone-Poulenc Rorer S.A.'s Application [1995] APO 50.