1: 2.) 5percent H2O2 / 1.) THF, -70 deg C, 2.) CH2Cl2, 1 h 2: 1.) n-BuLi / 1.) THF, n-hexane, -78 deg C, 5 min, 2.) THF, n-hexane, -78 deg C, 2 h View Scheme

1: diphenylphosphine oxide With potassium hydroxide; tetrabutylammomium bromide in tert-butyl methyl ether; water T=20°C; 0.25 h; 2: lt;3S-(1Z,3α,5β)gt;-2-lt;3,5-bislt;lt;(1,1-dimethylethyl)dimethylsilylgt;oxygt;-2-methylenecyclohexylidenegt;-1-chloroethane in tert-butyl methyl ether; water T=20°C; 2.08333 - 2.16667 h;

1: n-BuLi / hexane; tetrahydrofuran / 0.25 h / -50 °C 2: 3.00 g / aq. H2O2 / CHCl3 / 0.02 h View Scheme

dihydrogen peroxide 1.) THF, -70 deg C, 2.) CH2Cl2, 1 h; Yield given. Multistep reaction;

1: 2.) 5percent H2O2 / 1.) THF, -70 deg C, 2.) CH2Cl2, 1 h 2: 1.) n-BuLi / 1.) THF, n-hexane, -78 deg C, 5 min, 2.) THF, n-hexane, -78 deg C, 2 h View Scheme