pyridine 0.5 h; Heating;

1: 60 percent / pyridinium dichromate / CH2Cl2 / 18 h / 20 °C 2: 3.3 percent / Zn, 50percent aq. AcOH / 1.5 h View Scheme

ammonia; lithium in tetrahydrofuran 0.5 h;

methanol; acetic acid

acetic acid; zinc 1.5 h; Title compound not separated from byproducts;

malonic acid 19 h;

1: 2.55 g / TsOH / benzene / 2 h / Heating 2: 1.) tBuOK, 2.) TsOH / 1.) Et2O, -30 deg C, 24 h, 2.) acetone, TsOH, 2 h View Scheme

1: p-TSA / benzene / Heating 2: N-bromosuccinimide, MgO, H2O / dimethylformamide / 2 h / Ambient temperature 3: 71 percent / NaOMe / methanol; tetrahydrofuran / 8 h / 4 °C 4: 1) N,N,N',N'-tetramethylethylenediamine, 2) n-BuLi, CuI / 1) a) ethyl ether, dry ice, acetone bath, b) -15 deg C, 45 min, 2) -15 deg C, 20 min, 3) -20 deg C, 24 h 5: 0.25 g / p-TSA / acetone / 18 h / Ambient temperature 6: 93 mg / 1.0 M NaOH / methanol / 2 h / Heating View Scheme