The reaction of ethylidenemalonates 3a and a-cyanocrotonates 3b with crotylorganometals 2 such as B, Ti, Zr, and Sn reagents produced the anti adduct 4 predominantly. Similarly, the Michael addition of y-alkoxysubstituted allylmetals 6 to 3 gave the anti adduct 7 preferentially. The Michael addition of crotyltin 2e and (y-(methoxymethoxy) allyl) tin 6d to nitroolefins 20 again produced the anti isomers (21 and 23, respectively) predominantly. ...
