(4S,5S,6S)-4-[(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]-6-[(S)-1,3-dithian-2-yl(phenylmethoxy)methyl]-2,2-dimethyl-5-phenylmethoxy-1,3-dioxane                                                                                                                                                              在
                                                                                                                                                                                 
N-溴代丁二酰亚胺(NBS)   、                                                                                                  
silver nitrate                                                                                                                                  作用下,
                                                                                                                                                                                                                            以99%的产率得到(2S)-2-[(4S,5S,6S)-6-[(4S)-2,2-dimethyl-1,3-dioxolan-4-yl]-2,2-dimethyl-5-phenylmethoxy-1,3-dioxan-4-yl]-2-phenylmethoxyacetaldehyde