First Total Synthesis of MalvoneA and Formal Syntheses of Boryquinone and Hybocarpone Using a ConciseStrategy for Construction of Unsymmetrical Naphthoquinones

The first total synthesis of malvone A (1) is presented in seven steps along with a nine-step formal synthesis of boryquinone (2) and an eleven-step formal synthesis of hybocarpone (3). The overall strategy, which accesses compounds 7-12 for the first time, employs an easily constructed a-tetralone, and it has significant im- plications for synthesis of the naphthoquinone portion of b-rubro- mycin (4) as well as a host of other unsymmetrical and differentially protected naphthoquinones.