trans-ethyl-4-oxo-5-hydroxy-5-methylhex-2-enoate   、                                                                                      
3-[1]naphthyl-acrylaldehyde                                                                                                                                                              在
                                                                                                                                                                                 
(5aR,10bS)-5a,10b-dihydro-2-(2,4,6-trimethylphenyl)-4H,6H-indeno[2,1-b]-1,2,4-triazolo[4,3-d]-1,4-oxazinium chloride   、                                                                                                  
1,8-二氮杂双环[5.4.0]十一碳-7-烯                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲苯                                                                                  为溶剂,
                                                                                                                                                    反应 16.25h,
                                                                                                                以45%的产率得到(1S,2R,3R,5R)-ethyl-5-(2-hydroxypropan-2-yl)-2-(naphthalen-1-yl)-7-oxo-6-oxabicyclo[3.2.0]heptane-3-carboxylate