Application of oxo reaction to two sugar epoxides

Methyl 2,3-anhydro-4,6-0-benzylidene- α-D-mannopyranoside was allowed to react with carbon monoxide and methanol in the presence of dicobalt octacarbonyl at elevated temperatures and pressures. The resulting product mixture contained unreacted epoxide, methyl 3-0-methyl-α -D-altropyranoside and methyl 4,6-0-benzylidene- α-D-altropyranoside. Methyl 2,3-anhydro-4,6-0-benzylidene- α-D- mannopyranoside was allowed to react with carbon monoxide (990 p.s.i.) and hydrogen (910 p.s.i.) in the presence of dicobalt octacarbonyl at 140°. The resulting product mixture contained two products. The n.m.r. indicated that the epoxide ring had not been opened. In one product, the benzylidene ring was completely removed and in the other component the benzylidene ring had been partially altered. When Brigl's anhydride was allowed to react with carbon monoxide (910 p.s.i.) and hydrogen (990 p.s.i.) in the presence of dicobalt octacarbonyl at 106° for 30 minutes, the resulting product mixture contained one major product and two minor products. The minor product was presumed to be a sugar and the major product (75-80%) had been characterized as 2,6-anhydro-D-glycero-D-gulo-heptitol.Science, Faculty ofChemistry, Department ofGraduat