1-Cyclohexene-1-carboxaldehyde, 3-hydroxy-2-methyl-   、                                                                                      
4-hydroxy-6-(3,4-dimethoxyphenyl)-2-pyrone                                                                                                                                                              在
                                                                                                                                                                                 
L-脯氨酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
乙酸乙酯                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 (5aR,6S)-3-(3,4-dimethoxyphenyl)-6-hydroxy-5a-methyl-6,7,8,9-tetrahydropyrano[4,3-b]chromen-1-one   、                                                                                             (5aR,6R)-3-(3,4-dimethoxyphenyl)-6-hydroxy-5a-methyl-6,7,8,9-tetrahydropyrano[4,3-b]chromen-1-one