The aldol addition of an enol(ate) to a carbonyl compound is one of the most powerful and versatile C-C bond forming reactions. In complex target synthesis the coupling of two chiral partners may complicate the stereochemical outcome by multiple stereoinductions. Here, we report studies on pivotal aldol couplings employed in the rhizopodin synthesis, detailing the various directing effects exerted by the stereogenic centers present in this sterically hindered connection.
The aldol addition of an enol(ate) to a carbonyl compound is one of the most powerful and versatile C-C bond forming reactions. In complex target synthesis the coupling of two chiral partners may complicate the stereochemical outcome by multiple stereoinductions. Here, we report studies on pivotal aldol couplings employed in the rhizopodin synthesis, detailing the various directing effects exerted by the stereogenic centers present in this sterically hindered connection.
A highly convergent total synthesis of the potent polyketide macrolide rhizopodin has been achieved in 29 steps by employing a concise strategy that exploits the molecule′s C2 symmetry. Notable features of this convergent approach include a rapid assembly of the macrocycle through a site‐directed sequential cross‐coupling strategy and the bidirectional attachment of the side chains by means of Hor
Stereoselective Synthesis of 1,3-<i>anti</i> Diols by an Ipc-Mediated Domino Aldol-Coupling/Reduction Sequence
作者:Michael Dieckmann、Dirk Menche
DOI:10.1021/ol3033303
日期:2013.1.4
A novel domino process for 1,3-anti diol synthesis by the union of a methyl ketone with an aldehyde is described. The operationally simple procedure is based on an Ipc-boron-aldol coupling and subsequent Ipc-mediated reduction of the intermediate beta-hydroxy-ketone. The sequence proceeds with excellent anti-selectivities and enables the rapid construction of complex polyketide fragments.