sentences:  Conversely, a Kumada coupling using vinylic Grignard reagents proceeds without stereospecificity to form a mixture of "cis-" and "trans-"alkenes.The degree of isomerization is dependent on a variety of factors including reagent ratios and the identity of the halide group.According to Kumada, this loss of stereochemistry is attributable to side-reactions between two equivalents of the allylic Grignard reagent.