(S)-6-tert-Butoxycarbonylamino-2-(9H-fluoren-9-ylmethoxycarbonylamino)-hexanethioic acid S-pyridin-2-yl ester   、                                                                                      alkaline earth salt of/the/ methylsulfuric acid                                                                                                                                                                                              以
                                                                                         
四氢呋喃                                                                                  为溶剂,
                                                                                                                                                    反应 3.0h,
                                                                                                                以49%的产率得到[(S)-5-(9H-Fluoren-9-ylmethoxycarbonylamino)-6-oxo-6-phenyl-hexyl]-carbamic acid tert-butyl ester