乙酸酐   、                                                                                      
O-(2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl)-(1->2)-O-(3,4,6-tri-O-acetyl-α-D-mannopyranosyl)-(1->3)-O-(2,4,6-tri-O-acetyl-β-mannopyranosyl)-(1->4)-2-acetamido-3-O-acetyl-1,6-anhydro-2-deoxy-β-D-glucopyranose                                                                                                                                                              在
                                                                                                                                                                                 
三氟化硼乙醚                                                                                                                                  作用下,
                                                                                                                                                                                                                            以79.2%的产率得到O-(2,3,4,6-tetra-O-acetyl-α-D-mannopyranosyl)-(1->2)-O-(3,4,6-tri-O-acetyl-α-D-mannopyranosyl)-(1->3)-O-(2,4,6-tri-O-acetyl-β-mannopyranosyl)-(1->4)-2-acetamido-1,3,6-tri-O-acetyl-2-deoxy-D-glucopyranose