In the first total synthesis of ent-dioxepandehydrothyrsiferol, the signature trans-anti-trans 7,7,6-fused tricyclic polyether framework was constructed in a single bromonium-initiated epoxide-opening cascade that incorporates both endo- and exo-selective epoxide openings, each directed by the substitution pattern of the epoxide (methyl groups). This study thus demonstrates the feasibility of a possible biogenesis.

A complex derived from Ni(cod)2 and NHC-IPr catalyzes a three-component coupling reaction involving allenes, aldehydes, and organosilanes and transfers the axial chirality of the allene to a stereogenic center in the product with very high fidelity. An unexpected regioselectivity is observed; favored are allylic rather than homoallylic alcohol derivatives, corresponding to the unusual process of coupling two electrophilic atoms: the allene sp and aldehyde carbon atoms. In all cases, high enantioselectivity, high Z/E selectivity, and, with differentially substituted allenes, high site selectivity are observed. This transformation represents the first enantioselective multicomponent coupling process of allenes.

Upon exposure of up to 10 mol % tributylphosphine, electron-deficient 1,7-enynes undergo [3 + 2] cycloaddition to afford bicyclo[3:3:0] ring systems. In all but one case, products were obtained in >95:5 de, as determined by 1H NMR. This methodology enables concise and diastereoselective access to diquinane ring systems, whereby three contiguous stereogenic centers are set in a single manipulation.

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A nickel-catalyzed method for the three-component coupling of alkenes (ethylene and alpha olefins), aldehydes, and silyl triflates is described, and this process represents the first catalytic method for coupling aldehydes and alkenes to give allylic alcohol derivatives. Conceptually, the alkene functions as a replacement for an alkenylmetal reagent.