zinc in acetic acid 2.5 h; Ambient temperature;

3-chloro-benzenecarboperoxoic acid in chloroform T=0°C; 1 h;

1: 2.) 4-(dimethylamino)pyridine (DMAP) / 1.) Et2O, pentane, -78 deg C, 10 min, 2.) Et2O, pentane, RT, 16 h 2: 63 percent / Et2NH, n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 4 h, 2.) RT, 4 d 3: 1.) LDA / 1.) THF, hexane, from -78 to 50 deg C, 2.5 h, 2.) THF, hexane, RT, 1 h 4: 1.) O3/O2, 2.) BHT, 15percent aq. H2SO4, silica gel / 1.) CH2Cl2, -78 deg C, 2 min, 2.) CH2Cl2, 22 deg C, overnight View Scheme

1: 63 percent / Et2NH, n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 4 h, 2.) RT, 4 d 2: 1.) LDA / 1.) THF, hexane, from -78 to 50 deg C, 2.5 h, 2.) THF, hexane, RT, 1 h 3: 1.) O3/O2, 2.) BHT, 15percent aq. H2SO4, silica gel / 1.) CH2Cl2, -78 deg C, 2 min, 2.) CH2Cl2, 22 deg C, overnight View Scheme

1: 1.) n-BuLi, TMEDA / 1.) hexane, RT, 90 min, 2.) hexane, 0 deg, 30 min 2: 2.) 4-(dimethylamino)pyridine (DMAP) / 1.) Et2O, pentane, -78 deg C, 10 min, 2.) Et2O, pentane, RT, 16 h 3: 63 percent / Et2NH, n-BuLi / tetrahydrofuran; hexane / 1.) -78 deg C, 4 h, 2.) RT, 4 d 4: 1.) LDA / 1.) THF, hexane, from -78 to 50 deg C, 2.5 h, 2.) THF, hexane, RT, 1 h 5: 1.) O3/O2, 2.) BHT, 15percent aq. H2SO4, silica gel / 1.) CH2Cl2, -78 deg C, 2 min, 2.) CH2Cl2, 22 deg C, overnight View Scheme

phosphoric acid; dicyclohexyl-carbodiimide in dimethyl sulfoxide; benzene T=20°C; 21 h;

water; iron(II) sulfate in acetonitrile T=38°C; Rearrangement; 4 h; Further byproducts given;

1: 1.) LDA / 1.) THF, hexane, from -78 to 50 deg C, 2.5 h, 2.) THF, hexane, RT, 1 h 2: 1.) O3/O2, 2.) BHT, 15percent aq. H2SO4, silica gel / 1.) CH2Cl2, -78 deg C, 2 min, 2.) CH2Cl2, 22 deg C, overnight View Scheme

1: 81 percent / silica gel, 10percent oxalic acid / CH2Cl2 / 20 h 2: 1.) O3/O2, 2.) CF3COOH / 1.) CH2Cl2, -78 deg C, 2.) CDCl3 View Scheme

triethylamine in methanol Reduction; Heating;