A catalytic asymmetric entry to enantioenriched tertiary naphthoquinols via a facile tandem oxidation/ring-opening sequence

The tertiary naphthoquinol is a key structural component of the antitumor natural products spiroxins A–E. Herein we report the first catalytic asymmetric approach to the tertiary naphthoquinol C4′ stereogenic center present in the spiroxin framework, via tandem oxidation/ring-opening of a cyclic 3,4-epoxyalcohol. This new route allows a facile entry into relatively inaccessible tertiary naphthoquinols with high enantioselectivity and without the need of chiral auxiliaries.