Catalytic asymmetric hydrogenation to access spiroindane dimethyl acetic acid

Asymmetric hydrogenation of achiral spiroindene dimethyl acetic acid 2 with 4% of Ru(II)-Mandyphos in acetone produced (S)-spiroindane dimethyl acetic acid 1 in 86% isolated yield and 96.8:3.2 enantiomeric ratio.