(1S,4aS,8aS)-1-Methyl-6-oxo-5,6,8,8a-tetrahydro-1H,4aH-pyrano[3,4-c]pyran-4-carboxylic acid methyl ester   、                                                                                      
Pyrrolidine dimethylaluminium amide                                                                                                                                                                                              以
                                                                                         
苯                                                                                  为溶剂,
                                                                                                                                                                                        以98%的产率得到(4S,5S,6S)-5-Hydroxymethyl-6-methyl-4-(2-oxo-2-pyrrolidin-1-yl-ethyl)-5,6-dihydro-4H-pyran-3-carboxylic acid methyl ester