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Tubingensin B is an indole diterpenoid that has a synthetically challenging chemical structure. Michael Corsello, Junyong Kim and Neil Garg from the University of California, Los Angeles, now report the total synthesis of this bioactive natural product. Their approach relies on the strategic use of a transient aryne intermediate — an aromatic ring containing a strained triple bond — to construct tubingensin B's pentacyclic core and highlights the utility of such long-avoided intermediates for the assembly of challenging structural motifs. The natural product's structure — underscored by the use of aryne intermediates in its synthesis — is stylized on the cover.Article p944IMAGE: DANIEL CASPI, ELEMENT TWENTYSIX
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