Jacobsen's (R,R)-(salen)Co(III) catalyst; water; toluene-4-sulfonic acid 20 h; optical yield given as percent ee;

di-isopropyl azodicarboxylate; triphenylphosphine in toluene RefluxInert atmosphere;

(R,R)-(-)-[N,N(1)-bis(3,5-di-tert-butylsalicylidene)-1,2-cyclohexanediaminoat(2-)]manganese (III) chloride; water T=0 - 20°C;

1: (S)-2-bromo-(1,4)-butanediol With sodium hydride in tetrahydrofuran; mineral oil T=-5°C; 2.5 h; Inert atmosphere; 2: 1-bromomethyl-4-methoxy-benzene in tetrahydrofuran; N,N-dimethyl-formamide; mineral oil T=-5 - 20°C; 2.58333 h; Inert atmosphere;

1: sodium hydride / Inert atmosphere 2: acetyl chloride / methanol / Inert atmosphere 3: di-isopropyl azodicarboxylate; triphenylphosphine / Inert atmosphere View Scheme

1: acetyl chloride / methanol / Inert atmosphere 2: di-isopropyl azodicarboxylate; triphenylphosphine / Inert atmosphere View Scheme

1.1: L-proline / dimethyl sulfoxide / 1 h / 25 °C 2.1: methanol; sodium tetrahydroborate / dimethyl sulfoxide / 0.17 h / 0 °C 3.1: palladium 10 on activated carbon; hydrogen / ethyl acetate / 12 h / 760.05 Torr 4.1: di(n-butyl)tin oxide; p-toluenesulfonyl chloride; triethylamine / dichloromethane / 20 °C / |Inert atmosphere 4.2: 1 h / 20 °C View Scheme

1: Et3N, DMAP 2: Et3N 3: 1.) TsOH; 2.) TRITON B / 1.) MeOH; 2.) MeOH View Scheme