2-methoxy-3-(2,3,4,6-tetra-O-acetyl-β-D-mannopyranosyl-1-thio)-1,4-naphthoquinone                                                                                                                                                              在
                                                                                                                                                                                 
sodium methylate                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲醇                                                                                  为溶剂,
                                                                                                                                                    反应 0.5h,
                                                                                                                以76%的产率得到(2R,3S,4S,4aS,12aS)-2-hydroxymethyl-3,4-dihydroxy-3,4,4a,12a-tetrahydro-2H-naphtho[2,3-b]pyrano[2,3-e][1,4]-oxathiine-6,11-dione