条件：Stage #1: With chloroformic acid ethyl ester; trimethylphosphane In tetrahydrofuran；Stage #2: With titanium tetrachloride In chloroform；通用合成方案还包括（a）苯中回流共沸除水；（c）MCPBA in CH₂Cl₂；（d）苯中POCl₃
参考文献：Patent: WO2003/99274, 2003, A1. Location in patent: Page 271-272
