sentences:  Mevalonate synthesis begins with the beta-ketothiolase-catalyzed Claisen condensation of two molecules of acetyl-CoA to produce acetoacetyl CoA.The following reaction involves the joining of acetyl-CoA and acetoacetyl-CoA to form HMG-CoA, a process catalyzed by HMG-CoA synthase.In the final step of mevalonate biosynthesis, HMG-CoA reductase, an NADPH-dependent oxidoreductase, catalyzes the conversion of HMG-CoA into mevalonate, which is the primary regulatory point in this pathway.