Addition of the sodium salts of five branched-chain nitromethyl sugars in N,N-dimethylformamide to aqueous solutions of titanium(III) chloride (at pH 1) produced the respective, C-formyl, branched-chain carbohydrate derivatives 3- C-formyl-1,2:5,6-di- O-isopropylidene-α- d-glucofuranose, 5- O-acetyl-3-deoxy-3- C-formyl-1,2- O-isopropylidene-α- d-ribofuranose, methyl 4,6- O-benzylidene-2,3-dideoxy-3- C-formyl-α- d- ribo-hexopyranoside ( 6), benzyl 2-acetamido-4,6- O-benzylidene-2,3-dideoxy-3- C-formyl-α- d-allopyranoside ( 9), and benzyl 2-acetamido-4,6- O-benzylidene-2,3-dideoxy-3- C-formyl-α- d- erythro-hex-2-enopyranoside. The axial formyl groups in 6 and 9 were equilibrated under mild conditions to give the equatorial 3- C-formyl epimers methyl 4,6- O-benzylidene-2,3-dideoxy-3- C-formyl-α- d-arabino-hexopyranoside and benzyl 2-acetamido 4,6- O-benzylidene-2,3-dideoxy-3- C-formyl-α- d-glucopyranoside ( 10), respectively. The branched chain in 10 was readily elongated by using ethyl 2-(diethoxyphosphoryl)propionate, to give benzyl 2-acetamido-4,6- O-benzylidene-2,3-dideoxy-3- C-(2-ethoxycarbonyl)prop-1-enyl-α- d-glucopyranoside.