Tandem reactions semipinacol rearrangements

A copper-catalysed tandem trifluoromethylation/semipinacol rearrangement reaction of allylic alcohols has allowed difunctionalization of alkenes through simultaneous construction of a bond and a quaternary carbon centre (Scheme... [Pg.565]

Extension of the reaction to propargylic cyclobutenols results in a tandem carbene inser-tion-semipinacol rearrangement of the cyclobutenol ring, leaving the cyclopropyl ring intact (equation 81)151. [Pg.529]

Pan, C.-A., Wang, B.-M., Tu, Y.-Q., Song, Z.-L. Samarium-catalyzed tandem semipinacol rearrangement/Tishchenko reaction of a-hydroxy epoxides a novel approach to highly stereoselective construction of 2-quaternary 1,3-diol units. Angew. Chem., Int. Ed. Engl. 2001,40, 3877-3880. [Pg.653]

Scheme 1.20 A tandem semipinacol rearrangement/Schmidt reaction in the total synthesis of r+Vstemonamine ri31V ...

A palladium-catalysed tandem semipinacol rearrangement/direct arylation reaction using a-aryl isopropenyl-t-cyclobutanols has been reported (Scheme 138). ... [Pg.524]

A tandem semipinacol rearrangement/oxa-Michael addition protocol for the construction of spiro- or fused dihydrofuran products firom simple furan derivatives was developed using BF3 under mild reaction conditions (13CEJ5246). [Pg.210]

Other modifications of the Tishchenko reaction are also known, and catalytic cascade reactions are particularly interesting. Examples include combinations oflish-chenko with aldol reactions in the presence of achiral [169] and chiral catalysts [170], Tishchenko/esterification sequences [171], tandem semipinacol rearrangement/Tish-chenko reactions [172] and couplings of vinyl esters with aldehydes [173]. [Pg.212]

Preparation of 6-alkylidenebicyclo[3.2.1]octan-8-one via a tandem cross-metathesis/ semipinacol rearrangement reaction occurs with the Hoveyda-Grubbs II catalyst that serves as the Lewis acid for the rearrangement (Scheme 92). ... [Pg.501]

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