环戊二烯   、                                                                                      
(E)-1-((3aR,6aR)-3-tert-Butyl-4,4-dioxo-3a,4,6,6a-tetrahydro-1-oxa-4λ6-thia-2,5-diaza-pentalen-5-yl)-but-2-en-1-one                                                                                                                                                              在
                                                                                                                                                                                 
四氯化钛                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
二氯甲烷                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 ((3aR,6aR)-3-tert-Butyl-4,4-dioxo-3a,4,6,6a-tetrahydro-1-oxa-4λ
6-thia-2,5-diaza-pentalen-5-yl)-((1R,2R,3S,4S)-3-methyl-bicyclo[2.2.1]hept-5-en-2-yl)-methanone   、                                                                                             ((3aR,6aR)-3-tert-Butyl-4,4-dioxo-3a,4,6,6a-tetrahydro-1-oxa-4λ
6-thia-2,5-diaza-pentalen-5-yl)-((1S,2S,3R,4R)-3-methyl-bicyclo[2.2.1]hept-5-en-2-yl)-methanone