(4a
R)-7ξ-ethoxy-6
c-methoxy-2
c-phenyl-(4a
r,9a
t)-hexahydro-[1,3]dioxino[5,4-
e][1,4]dioxepin-9ξ-ol                                                                                                                                                              在
                                                                                                                                         potassium fluoride-dibenzo-18-crown-6 ether                                                                                                                                                                          作用下,
                                                                                                                以
                                                                                         
溶剂黄146   、                                                                                         
乙腈                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 
2,4-di-O-acetyl-5,7-O-benzylidene-3-deoxy-3-C-methoxycarbonyl-3-nitro-D-glycero-α-D-ido-heptoseptanoside