With  acetic acid; tetramethylammonium triacetoxyborohydride in  acetonitrile T=-45 - -25°C; Reduction; 72.25 h;   

Multi-step reaction with 5 steps 1.1: 83 percent / NaI / acetone / 120 h / Heating2.1: LDA / diethyl ether; hexane / 5 h / 0 °C2.2: 80 percent / diethyl ether; hexane / -100 - 20 °C3.1: 87 percent / MMPP / methanol / -15 °C / pH 74.1: TiCl4; DIPEA / CH2Cl2 / 1.5 h / -78 °C4.2: 64 percent / CH2Cl2 / 2 h / -78 °C5.1: 99 percent / Me4NHB(OAc)3; AcOH / acetonitrile / 72.25 h / -45 - -25 °C  

Multi-step reaction with 2 steps 1.1: TiCl4; DIPEA / CH2Cl2 / 1.5 h / -78 °C1.2: 64 percent / CH2Cl2 / 2 h / -78 °C2.1: 99 percent / Me4NHB(OAc)3; AcOH / acetonitrile / 72.25 h / -45 - -25 °C