Total Synthesis of the Marine Sesquiterpene Quinones Hyatellaquinone and Spongiaquinone

The synthesis of the marine sesquiterpene quinone (+)‐hyatellaquinone ( 1 ) was achieved starting from the sesquiterpene aldehyde (+)‐albicanal ((+)‐ 3 ) ( Schemes 3 and 4 ). Coupling of (+)‐albicanal with 2,3,5,6‐tetramethoxyphenyllithium led to the aryl‐sesquiterpene system, which was modified to the target molecule. Furthermore, the first total synthesis of the marine compound spongiaquinone ( 2 ) was carried out starting from ((−)‐albicanal (−)‐ 3 ) in a reaction sequence encompassing a stereoselective CC bond hydrogenation and a one‐pot AcOH elimination/demethylation reaction ( Schemes 7 and 10 ). The occurrence of 1,2‐ and 1,4‐benzoquinone forms of 1 and 2 depends on the pH of the solvent system.