Biomimetic chromanol cyclisation : a common route to to α-Tocotrienol and α-Tocopherol

Abstract

A common synthetic route to alpha-tocotrienol and alpha-tocopherol has been accomplished by a biomimetic cyclization that yields the chromanol ring.  The chirality at C2 of the chromanol was induced by a covalently attached chiral dipeptide.  Its terminal Asp participates in the enantioface-selective protonation of the double bond of the alpha-tocotrienol precursor I.  alpha-Tocotrienol was diastereoselectively hydrogenated to alpha-tocopherol