1.1: toluene-4-sulfonic acid / methanol / 6 h / 20 °C / Inert atmosphere 1.2: 2 h / 0 °C / Inert atmosphere 2.1: 1,8-diazabicyclo[5.4.0]undec-7-ene / N,N-dimethyl-formamide / 48 h / 110 °C 3.1: lithium aluminium tetrahydride / diethyl ether / 1 h / 50 °C / Inert atmosphere 4.1: platinum(IV) oxide; hydrogen / ethanol / 14 h / 20 °C / 760.05 Torr 5.1: triethylsilane; boron trifluoride diethyl etherate / dichloromethane / 22 h / 50 °C / Inert atmosphere View Scheme