Asymmetric, catalytic, and direct self-aldol reaction of acetaldehyde catalyzed by diarylprolinol.

An asymmetric, catalytic, and direct self-aldol reaction of acetaldehyde was catalyzed by diarylprolinol in NMP, affording the trimer acetal, which was generated by the reaction of the self-aldol product with another acetaldehyde molecule in a moderate yield with good enantioselectivity. Acetal is the synthetic equivalent of the self-aldol product, which can be converted into other synthetically useful compounds in one pot without compromising the enantioselectivity.