α-bromo-isovaleric acid-anhydride   、                                                                                      
(2S,4R,13R,14E,16Z,20R,21S,23S)-(+)-24-Amino-13-ethyl-20,21,23-trihydroxy-17-methoxymethyl-2,4-dimethyl-9-oxo-14,16-tetracosadiensaeure                                                                                                                                                              在
                                                                                                                                                                                 
三乙胺                                                                                                                                  作用下,
                                                                                                                以
                                                                                         
四氢呋喃   、                                                                                         
甲醇                                                                                  为溶剂,
                                                                                                                                                                                        以92%的产率得到(2S,4R,13R,14E,16Z,20R,21S,23S)-(+)-24-(2-Brom-3-methyl-1-oxobutylamino)-13-ethyl-20,21,23-trihydroxy-17-methoxymethyl-2,4-dimethyl-9-oxo-14,16-tetracosadiensaeure