Synthesis of chiral and achiral pyranenamine derivatives. Potent agents with topical ocular antiallergic activity.

The SS, RR and meso stereoisomers of pyranenamine SK&F 84210 were synthesized stereospecifically starting from commercially available (R)-(-)- or (S)-(+)-2,2-dimethyl-1,3-dioxolane-4-methanol. In addition, two achiral pyranenamines 19 and 26 were also synthesized. When evaluated by intravenous and topical routes in the rat passive ocular anaphylaxis (POA) assay, (SS)- and meso-2 as well as achiral compounds 19 and 26 were found to be more potent antiallergic agents than (RR)-2.