(R)-2-((4R,5R)-4,5-Dimethyl-5-((2-(trimethylsilyl)ethoxy)carbonyl)-1,3-dioxolan-4-yl)propanoic Acid is an intermediate in synthesizing Monocrotaline-d4 (M526002), a labelled Monocrotaline (M526000) which is a toxic pyrrolizidine alkaloid isolated from Crotalaria spp. It is used for inducing pulmonary diseases in rats.