5-ethyl-2-oxo-6-thioxo-1,2,3,6-tetrahydropyrimidine-4-carboxylic acid                                                                                                                                                              在
                                                                                                                                                                                 
溶剂黄146   、                                                                                                  
锌                                                                                                                                  作用下,
                                                                                                                                                                                        反应 1.0h,
                                                                                                                生成                                                 cis-5-ethyl-2-oxo-6-thioxo-1,2,3,6-hexahydropyridmidine-4-carboxylic acid   、                                                                                             trans-5-ethyl-2-oxo-6-thioxo-1,2,3,6-hexahydropyridmidine-4-carboxylic acid