A Radical-Based Synthesis of Lingzhiol

The polycyclic natural product lingzhiol
[(±)-1] was synthesized from dimethoxytetralone 8 via cyclization
of an intermediate benzylic radical, generated from spiroepoxide 14, onto an alkynyl substituent generating tetracyclic compound 13 with an exocyclic double bond. After oxidative cleavage
of the double bond of 13 and reduction of the keto function
of 23, the correct diastereomer, 12-syn, was converted to lingzhiol (1) via known
steps. In a similar manner, lingzhiol analogue 39 was
synthesized from 5-methoxy-1-tetralone (27).