Long-range steric interactions of the protecting groups of the 1,5-diol were harnessed for the successful atropselective macrolactonization (A) in the synthesis of the C-1027 chromophore framework (see scheme). Subsequent LiN(SiMe3)2/CeCl3-promoted acetylide addition to an aldehyde (B) in the setting of a rigid macrocycle formed the target nine-membered ring system with a highly strained diyne.
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Inoue et al. (2004) studied this question.