1: diethyl 2-allyl-2-hydroxypentanedioate With ruthenium trichloride; sodium periodate in water; ethyl acetate; acetonitrile T=20°C; 1 h; 2: ethanol With acetyl chloride T=0 - 20°C; 3: With trifluoroacetic acid 24 h; Heating;

1.1: 91 percent / AcCl / 20 h / 20 °C 2.1: 86 percent / NaI; In / H2O; ethanol / 20 °C 3.1: NaIO4; RuCl3 / ethyl acetate; acetonitrile; H2O / 1 h / 20 °C 3.2: AcCl / 0 - 20 °C 3.3: 1.18 g / CF3CO2H / 24 h / Heating View Scheme

1.1: 86 percent / NaI; In / H2O; ethanol / 20 °C 2.1: NaIO4; RuCl3 / ethyl acetate; acetonitrile; H2O / 1 h / 20 °C 2.2: AcCl / 0 - 20 °C 2.3: 1.18 g / CF3CO2H / 24 h / Heating View Scheme