摘要:
                                The (9S)-macrolide 1 (P = TBS) was prepared in 14 steps (5% yield) with 63% overall ds starting from the ethyl ketone (S)-2.  The C1-C7 and C8-C13 segments, 3 and 4, were obtained via boron enolate aldol reactions mediated by (+)- and (-)-(Ipc)2BOTf, respectively.