Sugar-substituted phosphines

Appropriately substituted cyclic sulfates undergo an elimination reaction when treated with phosphines such as triphenylphosphine and trimethyl-phosphine in suitable solvents. The reaction is visualized to proceed via a phosphium sulfate salt as shown in Scheme 75. In the case of sugar-derived cyclic sulfates, anhydro sugars 294 were isolated (94SC1157) (Scheme 76). 

Some approaches to the synthesis of 2- and 3-phosphonomethyl derivatives of D-arabinose are covered in Chapter 14, and the generation of a dialkyl phos-phonodithioyl radical from 7 and its addition to carbohydrate alkenes has allowed the synthesis of other C-phosphonomethyl-substituted sugar derivatives (Scheme 1). The phosphinic acid analogue 8 of cychc AMP has been prepared, and the olefin metathesis reaction, with a newer Grubbs catalyst, has been used to synthesize some carbohydrate cyclic phosphonates, e.g. 9. ... 

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