Description General description 2,2-Dimethylcyclopentanone is a ketone. Synthesis of various C-2 substituted vitamin D derivatives with a 2,2-dimethylcyclopentanone unit in side chains has been reported. Regioselective synthesis of 2,2-dimethylcyclopentanone, via its enolate precursor regioselectively obtained using the 2-pyrrolidone magnesium salt, has been reported. Application 2,2-Dimethylcyclopentanone enolate may be used as starting reagent in the enantioselective synthesis of chiral phosphines belonging to the P-aryl-2-phosphabicyclo[3.3.0]octane family (PBO). It may be used in the synthesis of: • 2,6,6-trimethyl-2-azaspiro[4.4]nonane-1,3-dione, a spirosuccinimide moiety of asperparaline A • novel spiropentanopyrrolizidine oxime alkaloids, namely 2′,3′,5′,6′,7′,7a′-hexahydro-2,2-dimethylspirocyclopentane-1 • δ,δ-dimethyl-δ-valerolactone, via Baeyer-Villiger oxidation Packaging 1, 5 g in glass bottle