Mild protocols for generating molecular complexity:: A comparative study of hetero-domino reactions based on the oxidant and the substitution pattern

A bicyclic unsaturated 1,2-diol framework was found to undergo an interesting set of domino reactions on treatment with oxidants. One-pot syntheses of seven-membered-ring-containing frameworks were achieved by a Pb(OAc)(4)-mediated domino process, while with other oxidants investigated, such as Mn(OAc)(3), Dess-Martin periodmane, PhI(OAc)(2), Ph3Bi(CO)(3), NaIO4, and NaBiO3, the domino process was interrupted halfway through. Finally, tetrapropylammonium perruthenate (TPAP-NMO), Pd(OAc)(2), pyridinium dichromate (PDC), and pyridimum chlorochromate (PCC) gave only allylic oxidation and further diketone formation without any of the bond cleavage that is necessary to initiate the domino process. The substrates were chosen to test the limits of reactivity of various unsaturated 1,2-diol derivatives and to provide guidelines for their use in constructing complex synthetic targets. In this article we provide details of the reaction conditions, preparation of the starting materials and characterization of the products, along with new, unpublished results. Information is assembled to facilitate comparison between the various oxidants, solvents and substitution patterns.