A Tandem Non-Aldol Aldol Mukaiyama Aldol Reaction.
نویسندگان
چکیده
منابع مشابه
A tandem non-aldol aldol Mukaiyama aldol reaction.
[reaction: see text] A new one-pot tandem aldol process is described in which a secondary epoxy silyl ether is converted into the 1,5-bis-silyloxy-3-alkanone in good yield. Thus, treatment of the epoxy silyl ether 8 with TBSOTf and base affords the silyl enol ether 9 via non-aldol aldol rearrangement and addition of benzaldehyde and TBSOTf gives the ketone 10 with 4:1 syn selectivity. The diast...
متن کاملUnexpected syn hydride migration in the non-aldol aldol reaction.
[structure: see text] Non-aldol aldol rearrangement of the epoxy silyl ether 13b afforded the expected anti methyl ketone 14, while the diastereomeric epoxy silyl ether 13a afforded the syn methyl ketone 8b via an unprecedented syn hydride migration. Calculations suggest that this unusual reaction proceeds via the carbocation, which cannot easily rotate due to steric hindrance.
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The development of efficient methods for the asymmetric Mukaiyama aldol reaction in aqueous solution has received great attention. We have developed a new series of chiral lanthanide-containing complexes that produce Mukaiyama aldol products with outstanding enantioselectivities. In this paper, we describe an optimized ligand synthesis, trends in stereoselectivity that result from changing lant...
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The vinylogous Mukaiyama aldol reaction (VMAR) allows efficient access to larger segments for complex natural product synthesis, primarily polyketides, through the construction of vicinal hydroxyl and methyl groups as well as di and tri-substituted double bonds in one single operation. In this review, we will highlight stereoselective protocols that have been used in natural product synthesis a...
متن کاملTotal synthesis of auripyrone A using a tandem non-aldol aldol/Paterson aldol process as a key step.
Extensive NMR investigation of the compounds revealed a complex spiroketal core capped at one end by a tetrasubstituted g-pyrone, residing in an anomerically favored configuration wherein all but the substituents are positioned equatorially except for the C10 methyl and the C11 acyloxy groups. Auripyrones A (1) and B (2) showed cytotoxicity against HeLa S3 cells with IC50 values of 260 and 480 ...
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ژورنال
عنوان ژورنال: ChemInform
سال: 2004
ISSN: 0931-7597,1522-2667
DOI: 10.1002/chin.200414079