合成路线1

The synthesis of the ligand begins with a thermal or photochemical head-to-head dimerization of acrylonitrile (I). The mixture of the resulting cis- and trans-1,2-cyclobutanedicarbonitrile(II a-b) is separated by distillation and the trans-compound (II b) is then transformed to 1,2-bis(aminomethyl)cyclobutane (III) by reduction with lithiumalanat. The dichloroplatinum complex (IV) is conveniently prepared from diamine (III) and potassium tetrachloroplatinate. This complex reacts with silver nitrate to give the nitrato-complex (V), which was not isolated. After passing through a column of a strong anion exchanger in the OH-form, the activated complex reacts in aqueous solution with L-lactic acid to form the lactato-complex D-19466 as a diastereomeric mixture. The general reaction sequence is outlined in scheme 14986401a.