The stereoselective access to stereotriads as important polyketide building blocks is reported on the basis of the Krische-type hydrogen-mediated syn-crotylation. The products were obtained with an extremely high diastereoselectivity (dr >99:1), and the newly formed syn stereocenters were controlled solely by the chiral catalyst. The stereochemistry was assigned by crystallography and HPLC for both product manifolds. This extension of the burgeoning transfer hydrogen methodology gives divergent asymmetric access to anti,syn and syn,syn polyketide stereotriads from the same α-chiral starting material and avoids potentially epimerizable aldehyde intermediates.

A robust synthetic approach to cis-γ-hydroxycarvone derivatives has been developed, enabling efficient access to synthetic building blocks for the growing family of bioactive sesterterpenoid natural products. Using this approach, an allyl bromide carvone derivative was used as the key building block for the total synthesis of the natural product phorbin A. This synthetic sequence also demonstrates the utility of benozyl enol ethers as an effective means of masking a β-ketophosphonate and their subsequent application in a one-pot benzoyl transfer-intramolecular Horner-Wadsworth-Emmons reaction.

A convergent synthetic route to the sesterterpenoid framework of the bioactive phorbaketal and alotaketal natural product families has been established. The synthetic approach hinges on a Hosomi-Sakurai coupling of complex acetal and allylsilane coupling partners, followed by DDQ-promoted oxidative cyclization of highly unsaturated advanced intermediates. This robust synthetic approach enables further investigations into the members of these natural product families and readily provides access to analogues for biological testing.