Stereoselective Synthesis of Novel (±)-trans-Dihydronarciclasine Analogues: Preparation of a Pivotal Intermediate Containing Two Methoxy Substituents

An efficient stereoselective synthesis of a pivotal intermediate, cyclic allyl alcohol derivative containing two methoxy groups [(±)-22], using for the preparation (±)-trans-dihydronarciclasine analogues was elaborated starting from easily available and inexpensive methyl gallate. This new synthetic route consists 17 reaction steps, provides an opportunity to obtain wanted alkaloid additional group at position 11, in ring A phenanthridone scaffold.