Glucose reaction with phosphorane

Another unique compound was found7(g) among the products of the reaction between 3,5,6-tri-O-methyl-D-glucose and acetylmethylene-phosphorane. An inflection at 222 nm in the electronic spectrum, and strong infrared absorption at 5.8 /am, indicated an a,/3-unsaturated, cyclic ketone structure.89 When this compound was allowed to react with methylmagnesium bromide, the product showed7 8 an absence... 

In ah initio calculations, the species was modeled separately with MgFj and with P03 as the central moiety. " In the case of MgFj , an energy minimum was obtained with a geometry that corresponded well with the X-ray structure. When modeled as P03 the species is unstable, and resembles instead a transition state for phosphoryl transfer (with a moderate barrier of 14kcalmol ) from substrate G6P to the product glucose-1,6-diphosphate. The computationally modeled reaction is concerted with no phosphorane intermediate. ... 

The preparation of die unsaturated derivatives 24 as a Z/E mixture by treatment of a 6-phosphorane with 2-furaIdehyde and its derivatives has been disclosed. The reaction was also applied to 6-phosphoranes of D-glucose and D-tagatose derivatives. 

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