R. Gandolfi et al., ENHANCEMENT IN FACIAL SELECTIVITY OF A PLANE NONSYMMETRIC DOUBLE-BONDINDUCED BY A CONJUGATING METHOXYCARBONYL GROUP, Tetrahedron letters, 37(4), 1996, pp. 517-520
Introduction of a methoxycarbonyl group on the plane nonsymmetric doub
le bond of 2,3-dioxa and 2,3-oxaza bicyclo[2.2.2]oct-5-enes brought ab
out a clear-cut increase in syn selectivity of their reactions with 1,
3-dipoles.