Unified synthesis of caged Garcinia natural products based on a site-selective Claisen/Diels–Alder/Claisen rearrangement
2004; National Academy of Sciences; Volume: 101; Issue: 33 Linguagem: Inglês
10.1073/pnas.0401932101
ISSN1091-6490
AutoresEric J. Tisdale, Irina Slobodov, Emmanuel A. Theodorakis,
Tópico(s)Synthetic Organic Chemistry Methods
ResumoA unified synthetic strategy toward caged Garcinia natural products has been designed and implemented. Central to the strategy is a tandem Claisen/Diels–Alder/Claisen rearrangement of a suitably substituted xanthone precursor to form forbesione (1a). Serving as a template, forbesione is then used to deliver representative members of this family, including desoxygaudichaudione A (4), desoxymorellin (5), and gambogin (10). Studies on the timing of this reaction cascade suggest that the C-ring Claisen/Diels–Alder rearrangement proceeds initially and is followed by the A-ring Claisen reaction. The electronic and steric effects that govern the outcome of this cascade are presented.
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