Asymmetric synthesis catalyzed by poly‐ L ‐alanine

Asymmetric addition of dodecanethiol to isopropenyl methyl ketone catalyzed by the terminal amino group of poly‐L‐alanine (PLA) and its terminal models was studied. When PLA was used as catalyst, the [α]D value of the product, 1‐(dodecylthiomethyl)ethyl methyl ketone, was larger than in the case of catalysis by the terminal models of PLA, indicating the importance of conformation of the polymer catalyst in asymmetric reaction. On the other hand, on addition of ethanol to the reaction system, the [α]D of the product was increased in each case.