Phosphorane sugar, synthesis

The second synthesis of 654 and 655 makes use350,351 of the Wittig reaction. The (methylthio)methyl ether 656 is converted into the chloromethyl ether 657, which reacts with triphenylphosphine to yield a crystalline phosphonium salt (658). Reaction of 658 with phenyllithium gives a phosphorane, treatment of which with acryl-aldehyde leads to ethers 654 and 655 in —50% yield. Pure trtms-diene 654 was obtained352 in a reversed way consisting in preparation of a sugar ether acrylaldehyde (660) by replacement of the p-tolylsulfonyl group in 659, followed by reaction of 660 with methylenetriphenyl-phosphorane. 

Zhdanov and Polenov have reported58 a synthesis of the first sugar phosphorane (70), which was shown to react with p-nitro-and o-hy-droxy-benzaldehyde, forming unsaturated ketoses 71 and 72, respectively. Attempted reactions with p-dimethylamino-, p-hydroxy-, and 2,4-dihydroxy-benzaldehyde were unsuccessful. The formation of the dienic ketose 72 is undoubtedly caused by /3-elimination of a methoxyl group during treatment of the reaction mixture with aqueous sodium hydroxide during isolation. 

Jarosz, S, Mach, M, Phosphonate versus phosphorane method in the synthesis of higher carbon sugars. Preparation of D-erythro-L-manno-D-gluco-dodecitol, J. Chem. Soc., Perkin. Trans. 1, 3943-3948, 1998. 

Jarosz, S, Salanski, P, Mach, M, Application of stabilized sugar-derived phosphoranes in the synthesis of higher carbon monosaccharides. First synthesis of a C-21-dialdose, Tetrahedron, 54, 2583-2594, 1998. 

The first synthesis of 289 and 290 started from the base-catalyzed addition of a sugar containing an isolated hydroxyl group to 2,7-dimethyl-3,5-octa-dyine-2,7-diol (286). Two enynyl ethers (287 and 288) were formed and separated, the partial hydrogenation over a Lindlar catalyst affording dienyl ethers 289 and 290. Alternatively, both ethers were prepared by a Wittig reaction from chloromethyl ether (291) a phosphonium salt (292) was prepared and converted into a phosphorane. Reaction with acrylaldehyde gave a mixture of 289 and 290. 

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