Distinction of diastereofaces at the α-position of chiral cyclic acetals
摘要:
Asymmetric 1,2- and 1,4-additions to substrates with an acetal as a chiral auxiliary have been studied. Among the tested substrates, C2-symmetrical 5c was most effective for 1,2-addition with MeTi(O-iPr)3. Furthermore, C2-symmetrical carbinol 5b has been found to be a potent H-1-NMR reagent for determination of optical purity of carboxylic acids with a chiral center at the alpha-position.