The asymmetric addition of alkynylzinc reagents, prepared in situ from dimethylzinc and 1- alkynes, to α-dinitrones derived from glyoxal and N-(4-isopropylbenzyl) hydroxylamine was investigated by utilizing dicyclohexyl (R, R)-tartrate as a chiral auxiliary. The addition reaction of methyl (2-phenylethynyl) zinc afforded the corresponding optically active C2- symmetric (R, R)-bis (hydroxylamine) derivative with enantioselectivities of 90% and 81% ...
