Benzoic acid (2R,3R,4S,5R,6R)-4,5-dihydroxy-6-hydroxymethyl-2-pent-4-enyloxy-tetrahydro-pyran-3-yl ester                                                                                                                                                              在
                                                                                                                                                                                 
吡啶   、                                                                                                  camphor-10-sulfonic acid                                                                                                                                  作用下,
                                                                                                                                                                                                                            生成                                                 Benzoic acid (4aR,6R,7R,8S,8aS)-8-(2-chloro-acetoxy)-6-pent-4-enyloxy-2-phenyl-hexahydro-pyrano[3,2-d][1,3]dioxin-7-yl ester