Trifluoromethanesulfonic acid in acetonitrile was found to efficiently catalyze Friedel-Crafts alkylations of 1,2,4-trimethoxybenzene with a variety of simple or functionalized aldehydes to provide di- or triarylmethanes in high yields. The operationally simple protocol allowed a short synthesis of the phenylpropanoid natural product (-)-tatarinoid C establishing its absolute configuration. Under the developed reaction conditions a benzylic alcohol instead of an aldehyde also underwent reactions with 1,2,4-trimethoxybenzene and other nucleophiles to afford unsymmetrically substituted compounds.

We report a traceless photocleavable linker for the automated glycan assembly of carbohydrates with free reducing ends. The reductive-labile functionality in the linker tolerates all commonly used reagents and protocols for automated glycan assembly, as demonstrated with the successful preparation of nine plant cell wall-related oligosaccharides, and is cleaved by hydrogenolysis.

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A general synthetic access to 3,3-disubstituted 1,4-diynes bearing a quaternary carbon center from acetylacetone was developed. The compounds were cyclized to the corresponding enol ethers by cationic gold complexes. The reactions occur in complete exo-selectivity in contrast to compounds incorporating an alkoxy substituent in the 3-position. A mechanistic rationale for this reversal of selectivity is provided.

The total synthesis of the human telomerase inhibitor γ-rubromycin in its racemic form was accomplished in 3.8 % overall yield. The key feature of this synthesis is an efficient acid-catalyzed spiroketalization for the construction of the spiroketal core. The required electronically well-balanced spiroketal precursor was obtained by the convergent assembly of a naphthyl-substituted aldehyde, an α-methoxyallyl-γ-silyl-substituted phosphonate as the central C3 building block, and a highly functionalized aryl Grignard reagent. Another key feature is the late-stage construction of the isocoumarin moiety and a simultaneous protodesilylation furnishing the known methyl aryl ether protected precursor of γ-rubromycin.