1: (R)-1,1'-binaphthyl-3,3'-bis(Ph2P=O)-2,2'-diyl-AlCl; PhOH / CH2Cl2 / 44 h / -40 °C 2: 90 percent / HCOOH; HCl(gas) / 1 h / 20 °C 3: DDQ / tetrahydrofuran / 1 h / 3 °C 4: 1 N aq. HCl / tetrahydrofuran / 3 - 20 °C View Scheme

1: (R)-1,1'-binaphthyl-3,3'-bis(Ph2P=O)-2,2'-diyl-AlCl; PhOH / CH2Cl2 / 44 h / -40 °C 2: 90 percent / HCOOH; HCl(gas) / 1 h / 20 °C 3: DDQ / tetrahydrofuran / 1 h / 3 °C 4: 1 N aq. HCl / tetrahydrofuran / 3 - 20 °C View Scheme

1: (R)-1,1'-binaphthyl-3,3'-bis(Ph2P=O)-2,2'-diyl-AlCl; PhOH / CH2Cl2 / 44 h / -40 °C 2: 90 percent / HCOOH; HCl(gas) / 1 h / 20 °C 3: DDQ / tetrahydrofuran / 1 h / 3 °C 4: 1 N aq. HCl / tetrahydrofuran / 3 - 20 °C View Scheme

bei mehrmonatigem Behandeln unter Ausschluss von Licht;