(5
R)-8
t-benzyloxy-2,2,6
c-trimethyl-(5
rO)-1,3,7-trioxa-spiro[4.4]non-9
c-yl 
O4,
O6-isopropylidene-2-methylamino-α-
L-2-deoxy-glucopyranoside                                                                                                                                                              在
                                                                                                                                                                                 
sodium hydroxide                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
甲醇   、                                                                                         
丙酮                                                                                  为溶剂,
                                                                                                                                                                                        生成                                                 
(3aS)-4t-((5R)-8t-benzyloxy-2,2,6c-trimethyl-(5rO)-1,3,7-trioxa-spiro[4.4]non-9c-yloxy)-7t-hydroxy-6c-hydroxymethyl-3-methyl-(3ar,7at)-tetrahydro-pyrano[3,4-d]oxazol-2-one