Method of producing EPD and analogues thereof

A method for the preparation of EPD or an analogue thereof according to formula I

• wherein R1 and R2 are independently selected from R3, SR3, SO2R3, N(R3)2, C(O)NR3, NC(O)R3, OR3, CO2R3, OC(O)R3, Cl, F, Br or I, and;
• R3 is selected from H, C1-C8 hydrocarbyl or poly(alkene oxide);
• said method comprising converting an intermediate compound of formula II
• to EPD or an analogue of formula I by one or more steps comprising methylenation.