Preparation of sugars with branched chains, a methylene badge, or c-1-phenyl substituents by the Ramirez dioxaphosphole condensation

Abstract

The products of condensation of 2,3-O-isopropylidene-D-glyceraldehyde with 4,5-dimethyl- and 4,5-tetramethylene-2,2,2-trimethoxy-1,3,2-dioxaphospholes, (1) and (2), were hydrolysed to the free sugars which were converted by acidified methanol into the corresponding mixture of glycosides. In this way were prepared the methyl pyranosides and furanosides of 1-deoxy-3-C-methyl-D-ribo-hexose [(7), (9), and (10)], and 1,2-C-tetramethylene-D-ribose [(11) and (13)]. Condensation of the same aldehyde withthe 4-phenyldioxaphosphole (3) led to 1-C-phenyl-D-lyxose (15) which was further characterized as the tetra-O-benzoate (16) and tetra-O-acetate (17) of the α-D-pyranoside tautomer.