1.1: tBuOK / tetrahydrofuran 1.2: 75 percent / tetrahydrofuran / 4 h / -30 - 20 °C 2.1: AcOH; H2O / tetrahydrofuran / 24 h / 20 °C 3.1: NaBH4 / methanol 4.1: CBr4; PPh3 / acetonitrile / 0 °C 4.2: 91 percent / 2,6-di-tert-butyl-4-methylpyridine / acetonitrile / -40 °C 5.1: tetrahydrofuran / -78 °C 6.1: LiHMDS / tetrahydrofuran / -78 °C 6.2: 80 percent / tetrahydrofuran 7.1: TMSOTf; collidine / CH2Cl2 / 1 h / 0 °C 7.2: 85 percent / nBu4NF / tetrahydrofuran 8.1: 2,4,6-trichlorobenzoyl chloride; Et3N / tetrahydrofuran / 1 h / 20 °C 8.2: 60 percent / DMAP / toluene / 80 °C 9.1: 86 percent / TFA / CH2Cl2 / 0 °C 10.1: 71 percent / 2,4,6-triisopropylbenzenesulfonyl hydrazide; Et3N / diethyl ether / 39 °C 11.1: dimethyldioxirane / CH2Cl2 / -50 °C View Scheme

1.1: tBuOK / tetrahydrofuran 1.2: 75 percent / tetrahydrofuran / 4 h / -30 - 20 °C 2.1: AcOH; H2O / tetrahydrofuran / 24 h / 20 °C 3.1: NaBH4 / methanol 4.1: CBr4; PPh3 / acetonitrile / 0 °C 4.2: 91 percent / 2,6-di-tert-butyl-4-methylpyridine / acetonitrile / -40 °C 5.1: tetrahydrofuran / -78 °C 6.1: LiHMDS / tetrahydrofuran / -78 °C 6.2: 80 percent / tetrahydrofuran 7.1: TMSOTf; collidine / CH2Cl2 / 1 h / 0 °C 7.2: 85 percent / nBu4NF / tetrahydrofuran 8.1: 2,4,6-trichlorobenzoyl chloride; Et3N / tetrahydrofuran / 1 h / 20 °C 8.2: 60 percent / DMAP / toluene / 80 °C 9.1: 86 percent / TFA / CH2Cl2 / 0 °C 10.1: 71 percent / 2,4,6-triisopropylbenzenesulfonyl hydrazide; Et3N / diethyl ether / 39 °C View Scheme