Effect of ethanol on the asymmetric synthesis catalyzed by poly(5‐benzyl L‐glutamate) and poly(4‐benzyl L‐aspartate)

In the asymmetric addition of dodecanethiol ( 1 ) to isopropenyl methyl ketone ( 3 ) catalyzed by the terminal amino group of poly(5‐benzyl L ‐glutamate) (PBLG) ( 7b ) and poly(4‐benzyl L ‐aspartate) (PBLA) ( 7a ), the effect of addition of ethanol was studied. In the reaction catalyzed by PBLG, the magnitude of the optical rotation of the addition product increased without changing the sign with the addition of ethanol. In the reaction catalyzed by PBLA, on the other hand, the sign of the optical rotation of the product was inverted with the addition of ethanol. The effect of ethanol was discussed in relation to the mechanism of the reaction as well as the conformation of the polymeric catalyst.