Acyl-2H-Pyran-3 6H -One

Feringa and coworkers [258] and O Doherty et al. [259] independently reported palladium-catalyzed glycosylations of 2-substituted 6-acyl-2H-pyran-3(6H)-one derivatives and alcohols (Scheme 5.98). This reaction presumably involves electrophilic Pd 7t-allyl complex intermediate, which was generated by the reaction of 2-substituted 6-acyl-2Ff-pyran-3(6H)-one and Pd(0)/PPh3. It is noteworthy that 2-substituted 6-acyl-2H-pyran-3(6H)-one derivatives were stereoselectively converted into 2-substituted 6 - a I k o x y - 2 H - p y r an - 3 (6 H) -o n e derivatives with complete retention of configuration by this reaction. A two-step reduction/oxidation manipulation after the glycosylation can install new stereocenters in the obtained glycosides. 

General Procedure for the Preparation of 6-Acyl-2H-Pyran-3(6H)-Ones froml-(2 -Furyl)-2-tert-Butyldimethylsilanyloxyethan-l-Ols... 

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