摘要:
Efforts toward a synthesis of (+/-)-fusidilactone C is described here featuring a novel cyclic acetal tethered intramolecular Diels-Alder strategy. This unique and facile IMDA turned out to be highly endo-selective [endo-I and endo-II], as assessed from our mechanistic analyses. When using protic solvents or Lewis acids, the endo-I selectivity was greatly enhanced. Thus, it proved to be a real challenge to circumvent this excellent stereochemical outcome, which is undesired for the total synthesis, as an exo-II selectivity is desired. Progress was made to use the endo-II cycloadduct and to access the desired trans-2-oxadecalin motif in (+/-)-fusidilactone C.