Organocatalytic Highly Enantioselective Synthesis of β‐Formyl‐α‐hydroxyphosphonates

The cross‐aldol reaction between enolizable aldehydes and α‐ketophosphonates was achieved for the first time by using 9‐amino‐9‐deoxy‐epi‐quinine as the catalyst. β‐Formyl‐α‐hydroxyphosphonates were obtained in high to excellent enantioselectivities. The reaction works especially well with acetaldehyde, which is a tough substrate for organocatalyzed cross‐aldol reactions. The products were demonstrated to have anticancer activities.