Js. Plummer et al., STEREOSELECTIVE MICHAEL ADDITIONS OF NITROMETHANE YIELDING 3R(1S N-SUBSTITUTED AMINOETHYL)PYRROLIDINES, Tetrahedron letters, 34(47), 1993, pp. 7529-7532
The 1,4-addition of nitromethane to vinylogous esters of N-protected a
mino acids proceeded with good to excellent yields and with good diast
ereoselectivity.