1: With diisobutylaluminium hydride in tetrahydrofuran; hexane T=0 - 5°C; 4 h; Inert atmosphere; 2: With L-tartaric acid dipotassium salt in tetrahydrofuran T=25°C; 0.5 h; Cooling with iceInert atmosphere;

1.1: thionyl chloride / 0 - 25 °C / Inert atmosphere 2.1: diisobutylaluminium hydride / tetrahydrofuran; hexane / 4 h / 0 - 5 °C / Inert atmosphere 2.2: 0.5 h / 25 °C / Cooling with ice; Inert atmosphere View Scheme

1.1: 1-methyl-pyrrolidin-2-one / 6 h / 160 - 165 °C / Inert atmosphere 2.1: thionyl chloride / 0 - 25 °C / Inert atmosphere 3.1: diisobutylaluminium hydride / tetrahydrofuran; hexane / 4 h / 0 - 5 °C / Inert atmosphere 3.2: 0.5 h / 25 °C / Cooling with ice; Inert atmosphere View Scheme

1.1: sodium perborate; acetic acid / 21 h / 65 - 70 °C / Inert atmosphere 2.1: 1-methyl-pyrrolidin-2-one / 6 h / 160 - 165 °C / Inert atmosphere 3.1: thionyl chloride / 0 - 25 °C / Inert atmosphere 4.1: diisobutylaluminium hydride / tetrahydrofuran; hexane / 4 h / 0 - 5 °C / Inert atmosphere 4.2: 0.5 h / 25 °C / Cooling with ice; Inert atmosphere View Scheme