Studies on intramolecular alkylation. VI. <i>ortho</i> -Alkylation in phenolic diazoketones: the preparation of intermediates containing the Cyclohexa-2,4-dienonemoiety suitable for gibberellin synthesis

Abstract

Simple efficient syntheses of 8-hydroxy- and 8-methoxy-2-tetralones (9) and (10), 1,2,3,4-tetrahydro-8- hydroxy-2-naphthoic acid (5), 1,2,3,4-tetrahydro-2-hydroxy-8-methoxy-2-naphthoic acid (8), 1,2,3,4-tetrahydro-2,s-dihydroxy-2-naphthoic acid (7) and 1,2,3,4-tetrahydro-5-hydroxy-2-naphthoic acid (20) are described. The acid-catalysed reactions of the diazoketones derived from (5) and (20) gave good yields of tricyclic ketones (3) and (4) incorporating a cyclohexa-2,4-dienone moiety. The potential of (3) for gibberellin synthesis is examined.