The Boron-Mediated Ketone—Ketone Aldol Reaction.
نویسندگان
چکیده
منابع مشابه
The boron-mediated ketone-ketone aldol reaction
The first examples of the directed, boron-mediated aldol reaction between different ketones are presented. Transformation of a variety of ketones to their corresponding boron enolates with Chx2BCl/Et3N, followed by reaction with acceptor ketones in diethyl ether, and oxidation of the resultant boron aldolate (H2O2, MeOH/pH 7 buffer), provided the aldol addition products. The reaction was most f...
متن کاملA 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 کاملEnantioselective synthesis of anti- and syn-β-hydroxy-α-phenyl carboxylates via boron-mediated asymmetric aldol reaction.
A reagent-controlled, diastereo- and enantioselective synthesis of anti- and syn-β-hydroxy-α-phenyl carboxylates has been achieved by the proper choice of solvent, temperature, alkoxy group, and amine for the diisopinocampheylboron-mediated asymmetric enolization-aldolization of phenylacetates. The pure diastereomers can be readily separated by column chromatography.
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.
متن کاملOrganic Synthesis: Aldol Condensation Reaction
In an "aldol addition" reaction an enol or enolate of an aldehyde or ketone reacts with a second aldehyde or ketone forming a new carbon-carbon bond which makes the aldol reaction an important reaction for organic synthesis. Originally, the aldol reaction used ethanal (see below) and therefore the product contained both an aldehyde and an alcohol functional group; thus it became known as the al...
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ژورنال
عنوان ژورنال: ChemInform
سال: 2005
ISSN: 0931-7597,1522-2667
DOI: 10.1002/chin.200526046