dimethyl 2-((1R,2R)-2-methyl-1-(4-nitrophenyl)-3-oxopropyl)malonate                                                                                                                                                              在
                                                                                                                                                                                 
sodium cyanoborohydride   、                                                                                                  
溶剂黄146                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 
(3R,4R,5R)-methyl 5-methyl-4-(4-nitrophenyl)-2-oxo-tetrahydro-2H-pyran-3-carboxylate   、                                                                                             methyl 5-methyl-4-(4-nitrophenyl)-2-oxo-tetrahydro-2H-pyran-3-carboxylate