(3aR,6aR)-2,2-dimethyl-2H,3aH,4H,6aH-cyclopenta(d)(1,3)dioxol-4-one

CAS 115509-13-2

How can one small ring support a complex synthesis? CAS 115509-13-2 is a chiral cyclopentenone with two oxygen-bearing stereocenters protected by an acetonide. Its enone offers reaction sites while the oxygen functions remain temporarily masked. A 2009 paper explicitly used this intermediate in a route to triazolo-carbanucleosides, transforming it into a more elaborate cyclopentane azide before constructing triazole-containing products. The starting ketone is not itself a nucleoside or a demonstrated medicine. Its contribution is synthetic: defined chirality, a carbon-ring framework, and functional groups that can be changed in a planned order. This illustrates why an intermediate can be scientifically interesting even when the biological properties belong to later products. Protecting groups organize timing; stereochemistry organizes the starting three-dimensional arrangement for subsequent molecular construction.