A novel 18-membered chiral crown ether was prepared in four steps starting from L-quebrachitol, a chiro-inositol, and its catalytic activity in the Michael addition reaction of glycine imine with several Michael acceptors was studied.
The reduction of alpha-keto esters derived from (1L)-1,2;5, 6-biscyclohexylidene-3-tert-butyldimethysilyl-chiro-inositol with Selectride(R) proceeded with high diastereoselectivity to afford the corresponding alpha-hydroxy esters. Addition of 18-Crown-6 led to dramatic changeover in diastereofacial selectivity.
AKIYAMA, TAKAHIKO;TAKECHI, NAOTO;SHIMA, HIROAKI;OZAKI, SHOICHIRO, CHEM. LETT.,(1990) N0, C. 1881-1884