Synthesis of new substituted 7,12-dihydro-6,12-methanodibenzo[<i>c,f</i>]azocine-5-carboxylic acids containing a tetracyclic tetrahydroisoquinoline core structure
A convenient and simple protocol has been developed for the synthesis of a series of new tetracyclic tetrahydroisoquinoline derivatives, 7,12-dihydro-6,12-methanodibenzo[c,f]-azocine-5-carboxylic acids by three component Petasis reaction with the use of aminoacetaldehyde acetals bearing substituted benzyl groups as the amine components followed by Pomeranz–Fritsch double cyclization reaction. By applying