zinc(II) chloride in benzene 4 h; Heatingalso in refluxing toluene; acid additives and their quantity varied; time; Product distribution;

1.1: 73.9 percent / conc. sulfuric acid / acetic acid / 10 h / 100 °C 2.1: DIBAL-H / toluene / 2 h / 0 °C 3.1: 56.5 percent / pyridinium chlorochromate; sodium acetate / CH2Cl2 / 1 h / 20 °C 4.1: n-butyllithium / tetrahydrofuran; hexane / -78 °C 4.2: tetrahydrofuran; hexane / -78 °C 5.1: 1.06 g / p-toluenesulfonic acid / tetrahydrofuran; H2O / 24 h / 20 °C 6.1: 83.5 percent / NaH; n-BuLi / tetrahydrofuran; hexane / 3 h / -10 °C View Scheme

1.1: 73.9 percent / conc. sulfuric acid / acetic acid / 10 h / 100 °C 2.1: DIBAL-H / toluene / 2 h / 0 °C 3.1: 56.5 percent / pyridinium chlorochromate; sodium acetate / CH2Cl2 / 1 h / 20 °C 4.1: n-butyllithium / tetrahydrofuran; hexane / -78 °C 4.2: tetrahydrofuran; hexane / -78 °C 5.1: 1.06 g / p-toluenesulfonic acid / tetrahydrofuran; H2O / 24 h / 20 °C View Scheme

pyridine in dichloromethane

nitric acid; sodium nitrite 1.) water, below 5 deg C; 2.) water, below 5 deg C; Yield given. Multistep reaction;