1: H2SO4 / acetone 2: 52 percent / AlCl3, Me2S / CH2Cl2 / -10 °C 3: 68 percent / 5percent HCl / acetone / 24 h / 55 °C View Scheme

1: 91 percent / 5percent aq. HCl / tetrahydrofuran / 24 h 3: 74 percent / 5percent aq. HCl / acetone / 96 h 4: 68 percent / Oil Violet, ozone / ethanol / -75 °C 5: 85 percent / sulphamic acid, sodium chlorite / tetrahydrofuran; H2O / 3 h 6: 87 percent / H2SO4 / acetone / 30 h 7: 52 percent / Me2S, aluminium chloride / CH2Cl2 / 24 h 8: 68 percent / 5percent aq. H2SO4 / acetone / 48 h / Heating View Scheme

120 h; Penicillium brefeldianum Dodge (NRRL 2083);