“…( R )-3-Hydroxy-2-methylpropanoate ( 23b ), commonly denoted as ‘Roche-Ester’, is a popular chiral building block for the synthesis of vitamins (vitamin E), fragrance compounds (muscone), antibiotics (rapamycin) and natural products (Stueckler et al, 2010c). Prominent routes for its preparation include enzymatic oxidation of prochiral diols (Molinari et al, 2003) or the transition metal-catalyzed asymmetric hydrogenation of acrylate esters using Rh- (Holz et al, 2008; Qiu et al, 2009; Wassenaar et al, 2008) or Ru-catalysts (Pautigny et al, 2008).…”