(5RS,6SR,7SR,10RS)-5-hydroxy-10-methyl-3,4,5,6,7,8-hexahydro-5,6-propano-2H-1-benzopyran-6-propanenitrile                                                                                                                                                              在
                                                                                                                                                                                 
2-萘磺酸                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
苯                                                                                  为溶剂,
                                                                                                                                                    反应 1.0h,
                                                                                                                以31%的产率得到(4aSR,5SR,10bRS,12RS)-12-methyl-4,4a,5,6,9,10-hexahydro-3H,8H,5,10b-propanopyrano<2,3-h>quinolin-2(1H)-one