(OEP)RhIII(ClO4) to promote enolization of simple ketones by activation with charge-separated [(OEP)RhIII+ (a Lewis acid) under mild and neutral conditions. The second-order rate constant of (OEP)RhIII(ClO4)-assisted enolization of acetone at 30°C (k2 = 2.6 × 10−4 M−1 sec−1) is 107 times as large as that of its spontaneous enolization in water, where water is both acid and bse.
Platinum-Catalyzed Cyclization/[1,2]-Alkyl Migration/Allyl Shift/Cyclization Cascade of Epoxy Alkynyl Allyl Ethers: A Step-Economical Route to Spirobenzo[h]chromanones
In tandem: A PtI4‐catalyzed tandemreaction of epoxy alkynyl allyl ethers involving a cyclization, [1,2]‐alkyl migration, O→C allyl shift, aromatic cyclization sequence has been achieved to synthesize spirobenzo[h]chromanones. The reaction simultaneously forms two adjacent stereocenters, one of which is a quaternary carbon atom (see scheme).
串联:环氧炔基烯丙基醚的PtI 4催化串联反应,涉及环化,[1,2]-烷基迁移,O→C烯丙基转移,芳族环化顺序,以合成螺并苯并[ h ]苯并二氢呋喃。该反应同时形成两个相邻的立体中心,其中一个是季碳原子(请参阅方案)。
An Efficient Procedure for the Preparation of (<i>E</i>)-α-Alkylidenecycloalkanones Mediated by a CeCl<sub>3</sub>·7H<sub>2</sub>O−NaI System. Novel Methodology for the Synthesis of (<i>S</i>)-(−)-Pulegone<sup>1</sup>
synthons used as the key intermediates in many important syntheses. Because of their potential, a general method of preparation from readily available starting materials, under very mild conditions, was considered to be worthwhile. Cerium(III) chlorideheptahydrate in combination with sodiumiodide in refluxing acetonitrile promotes a regio- and stereoselective beta-elimination reaction to (E)-2-alky
gave methyl 2-vinylidene-1-cyclopentanecarboxylate and methyl trans-2-(1-methoxyalkyl)-1-cyclopentanecarboxylate along with 6-methoxy-2-vinylidenecyclohexanone via a Michael addition-induced Favorskiirearrangement.
One Pot Synthesis of α,β-Unsaturated Ketones from the Mukaiyama Aldol Condensation
作者:Ezzeddine Bouhlel、Béchir Ben Hassine
DOI:10.1080/00397919208019070
日期:1992.8
Abstract Satisfactory yields of α,β-unsaturatedketones are obtained from two trimethylsilylenol ethers and a variety of aldehydes and ketones in a onepot modified Mukaiyama aldol procedure using triethylamine and trifluoroacetic anhydride.