Lewis Acid Promoted Mukaiyama Aldol-Prins (MAP) Cyclizations of Acetals, Ketals, α-Acetoxy Ethers, and Orthoformates
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چکیده
منابع مشابه
Chemoselective silyl transfer in the Mukaiyama aldol reaction promoted by super silyl Lewis acid.
In the silyl Lewis acid-promoted Mukaiyama aldol reaction, the steric and electronic properties of the silyl group on the silyl Lewis acid influence the reaction mechanism and product distribution. When super silyl triflates such as (TMS)3SiOTf and (TES)3SiOTf are used as Lewis acids, the silyl group of the silyl enol ether chemoselectively transfers to the product. The mechanistic details have...
متن کاملOne-pot enol silane formation-Mukaiyama aldol-type addition to dimethyl acetals mediated by TMSOTf.
Various ketones, esters, amides, and thioesters add in high yield to dimethyl acetals in the presence of silyl trifluoromethanesulfonates and an amine base. Acetals derived from aryl, unsaturated, and aliphatic aldehydes are all effective substrates. The reaction proceeds in a single reaction flask, with no purification of the intermediate enol silane necessary.
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 کاملAn efficient catalyst-free Mukaiyama-aldol reaction of fluorinated enol silyl ethers with tryptanthrin.
We report an efficient Mukaiyama-aldol reaction of tryptanthrin with fluorinated enol silyl ethers, which is carried out in methanol without the use of any catalyst. This method is applied to the total synthesis of the difluoro analogues of the natural product Phaitanthrin B.
متن کاملThe Mukaiyama aldol reaction: 40 years of continuous development.
A directed cross-aldol reaction of silyl enol ethers with carbonyl compounds, such as aldehydes and ketones, promoted by a Lewis acid, a reaction which is now widely known as the Mukaiyama aldol reaction. It was first reported in 1973, and this year marks the 40th anniversary. The directed cross-aldol reactions mediated by boron enolates and tin(II) enolates also emerged from the Mukaiyama labo...
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ژورنال
عنوان ژورنال: Synlett
سال: 2008
ISSN: 0936-5214,1437-2096
DOI: 10.1055/s-2008-1032053