1.1: tributyltin chloride; sodium cyanoborohydride; AIBN / 2-methyl-propan-2-ol / 6 h / 90 °C 2.1: 78 percent / aq. CrO3; H2SO4 / acetone 3.1: lithium diisopropylamide / tetrahydrofuran; hexane / 3 h / 0 °C 3.2: HMPA / hexane; tetrahydrofuran / 1 h / 20 °C 4.1: (DHQD)2PHAL; aq. K3Fe(CN)6; OsO4 / 2-methyl-propan-2-ol / 16 h / 0 °C View Scheme

1.1: tributyltin chloride; sodium cyanoborohydride; AIBN / 2-methyl-propan-2-ol / 6 h / 90 °C 2.1: 78 percent / aq. CrO3; H2SO4 / acetone 3.1: lithium diisopropylamide / tetrahydrofuran; hexane / 3 h / 0 °C 3.2: HMPA / hexane; tetrahydrofuran / 1 h / 20 °C 4.1: (DHQD)2PHAL; aq. K3Fe(CN)6; OsO4 / 2-methyl-propan-2-ol / 16 h / 0 °C View Scheme

1: tributyltin chloride; sodium cyanoborohydride; AIBN / 2-methyl-propan-2-ol / 6 h / 90 °C 2: 78 percent / aq. CrO3; H2SO4 / acetone View Scheme