Pyrrolidine catalyzed diastereoselective direct aldol reaction in water: A green approach

The pyrrolidine catalyzed direct diastereoselective aldol reaction of different cyclic ketones and aromatic aldehydes has been performed in water. The aldol products are formed in high yield (up to 91%) and diastereoselectivity (up to >99:1 (anti:syn)) in a short reaction time (20-65 min) using only 10 mol% of pyrrolidine as catalyst. Moreover a co-relation between the ring size of donor ketones and diastereoselectivity of aldol products has also been observed. The methodology developed is green and highly efficient.