Palladium-catalyzed asymmetric allylic alkylation of cyclic dienol carbonates: Efficient route to enantioenriched γ-butenolides bearing an all-carbon α-quaternary stereogenic center
Alpha, beta, gamma: Allyl dienol carbonates (1) served as substrates for the title reaction to afford the furanones 2 in both high yields and high enantioselectivities. These furanones were eventually converted into valuable building blocks including γ-tertiary and γ-quaternary furanones (3) as well as β-quaternary butyrolactones (4). This method was used as a key step in the total synthesis of (-)-nephrosteranic acid and (-)-roccellaric acid. Copyright