Rapid Access to cis-1,3-Dialkylindanes: Asymmetric Formal Syntheses of epi-Mutisianthol and epi-Jungianol

Concise and strategically unique asymmetric formal syntheses of epi-mutisianthol and epi-jungianol are presented. A novel disconnection approach is introduced to complement previous intramolecular cyclopentannulation strategies. Noteworthy features include: (a) the control of the stereogenic benzylic carbon center through 1,3-chirality transfer from chiral indenols via the Johnson-Claisen rearrangement, which yields advanced indene-containing γ,δ-unsaturated esters, and (b) the diastereoselective construction of the cis-1,3-dialkylindane backbone via catalytic hydrogenation of the resulting indene. This approach presents a remarkable method for synthesizing structurally intriguing indane motifs.