Robert K. Ness

1,3,4,6-tetra-O-benzyl-d-fructofuranose and some of its derivatives

Abstract Crystalline 1,3,4,6-tetra- O -benzyl- d -fructofuranose ( 4 ) has been obtained in 60% overall yield from d -fructose through the following steps: d -fructose→methyl tetra- O -benzyl- d -fructofuranoside→ 4 . The new d -fructofuranose derivative has been further characterized through the preparation of a p -nitrobenzoate, a p -phenylazobenzoate and a benzoate — all crystalline derivatives. To confirm the structure of 4 , it was also made through the hydrolysis of octa- O -benzylsucrose and by the partial oxidation of 1,3,4,6-tetra- O -benzyl- d -mannitol ( 11 ); the preparation of 11 and of two crystalline derivatives therefrom is described.

Two benzylated hydroxyglycals derived from d-fructofuranose

Abstract 1,3,4,6-Tetra- O -benzyl- d -fructofuranosyl chloride ( 2 ), readily preparable from 1,3,4,6-tetra- O -benzyl- d -fructofuranose ( 1 ), undergoes dehydrohalogenation with ease to give two amorphous, unsaturated products (I and II). The 100-MHz p.m.r. spectra of these compounds permitted tentative assignments of structure, and these assignments were confirmed through chemical degradation. Periodate-permanganate oxidation of one of the unsaturated compounds (I) afforded 2,4-di- O -benzyl- d -erythronic acid ( 7 ), an authentic specimen of which was prepared through the periodate-hypoiodite oxidation of 3,5-di- O -benzyl- d -ribofuranose ( 8 ). This unsaturated compound is, therefore, 2,5-anhydro-1,3,4,6-tetra- O -benzyl- d - erythro -hex-2-enitol ( 3 ). Similar oxidation of the other unsaturated product (II) afforded the known 1,4-lactone of 2,3,5-tri- O -benzyl- d -arabinonic acid ( 6 ), showing that the double bond is exocyclic and that compound II is 2,5-anhydro-1,3,4,6-tetra- O -benzyl- d - arabino -hex-1-enitol ( 4 ).