In 1996, auripyrones A and B were isolated from the sea hare Dolabella auricularia (Aplysiidae) by Yamada and co-workers. Auripyrones A and B exhibited cytotoxicity against HeLa S_3 cells with an IC_<50> values of 0.26 and 0.48μg/mL, respectively. The main structural features of auripyrones are a γ-pyrone ring and a spiroacetal moiety. We planned the synthesis of auripyrones A and B by using diastereoselective aldol-type reaction with 2,6-diethyl-3,5-dimethyl-4-pyrone as a key step and have developed an efficient aldol-type reacton with 2,6-diethyl-3,5-dimethyl-4-pyrone. This key reaction has the benefit of straightforward access even to complex molecules and the construction of two stereogenic centers at once. Furthermore, we have achieved the total synthesis of auripyrone A by using this aldo-type reaction.
