1,4-bis(9-O-dihydroquinidine)phthalazine in water; tert-butyl alcohol T=20°C; Sharpless asymmetric dihydroxylation; 2 h;

ethanol; potassium carbonate; tetrakis(triphenylphosphine) palladium(0) 3 h; Heating;

osmium(VIII) oxide; 2,3-diphenyl-5,8-bis-(9-O-dihydroquinidine)pyrazinolt;2,3-dgt;pyridazine; potassium carbonate; potassium hexacyanoferrate(III) in toluene; tert-butyl alcohol T=0°C; 72 h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

1: 65 percent / BuLi / tetrahydrofuran / 0 - 25 °C 2: aq. K3Fe(CN)6, K2CO3, (DHQD)2-DPP, OsO4 / 2-methyl-propan-2-ol; toluene / 72 h / 0 °C View Scheme

1: 94 percent / DMAP; Et3N / CH2Cl2 / 2 h / 20 °C 2: 94 percent / t-BuOK / acetonitrile / 12 h / 20 °C 3: 98 percent / TBAF / acetonitrile / 4 h / 20 °C 4: 82 percent / TEMPO; NaClO; NaClO2 / acetonitrile; aq. phosphate buffer / 4 h / 55 °C View Scheme