Catalytic Asymmetric Hydrogenation of δ-Ketoesters: Highly Efficient Approach to Chiral 1,5-Diols

High turnover: An highly efficient catalytic asymmetric hydrogenation of δ-aryl-δ-ketoesters has been realized by using the chiral spiroiridium catalyst (R)-1. Chiral 1,5-diol products are obtained with excellent enantioselectivity and turnover numbers (TONs) as high as 100 000. TOF=turnover frequency.