Proceeding through at least eight individual steps and ending with a d
imerization, the domino cationic transformation of 1 leading to 2 prov
ides a new synthetic approach to bis(furanosides). Domino processes ar
e of current interest in organic synthesis, especially when the reacti
on requires many single steps and furnishes interesting products with
high regio- and stereocontrol. a, R1 = H, R2 = Me; b = R1 = R2 = H: c,
R1 = Et, R2 = H.