Iron Trichloride-Mediated Cascade Reaction of Aminosugar Derivatives for the Synthesis of Fused Tetrahydroisoquinoline-Tetrahydrofuran Systems.

A method to obtain tetrahydroisoquinolines (THIQs) fused to tetrahydrofuran rings from aminosugar derivatives has been developed. The procedure relies on a key deprotection of benzyl ethers followed by a double-cyclization sequence, using FeCl3 as the sole reagent. This tandem reaction affords the construction of novel fused polycyclic heterocycles with total stereochemical control.