1: 98 percent / i-Bu2AlH / CH2Cl2 / 1.5 h / -78 °C 2: 94 percent / piperidine / acetonitrile / 48 h / 5 °C 3: 90 percent / diisopropylethylamine / CH2Cl2 / 23 °C 4: 87 percent / HOAc, H2O (3:1) / 5 h / 23 °C 5: 93 percent / 0.15 M LiOH / 24 h / 23 °C / MeOH, H2O (6:1) 6: 1.) lactonization, 2.) MEM ether cleavage View Scheme