ent-3β,10β-dihydroxy-13-methyl-16-oxo-17,20-bisnor-8,13-isogibberellane-7,19-dioic acid 19,10β-lactone 7-methyl ester                                                                                                                                                              在
                                                                                                                                                                                 
四氯化碳   、                                                                                                  
三苯基膦                                                                                                                                  作用下,
                                                                                                                                                                                        反应 4.0h,
                                                                                                                以790 mg的产率得到ent-3α-chloro-10β-hydroxy-13-methyl-16-oxo-17,20-bisnor-8,13-isogibberellane-7,19-dioic acid 19,10β-lactone 7-methyl ester