lithium aluminium tetrahydride; triethyl amine hydrochloride in tetrahydrofuran T=0 - 20°C;

With  boron trifluoride diethyl etherate in  dichloromethane 2 h;   

Multi-step reaction with 2 steps 1.1: dicyclohexyl-carbodiimide; 1-hydroxy-pyrrolidine-2,5-dione / ethyl acetate / 6 h / |Inert atmosphere1.2: |Inert atmosphere2.1: boron trifluoride diethyl etherate / dichloromethane / 2 h / |Inert atmosphere2.2: |Inert atmosphere