Toward a Total Synthesis of the Novel Polyketide Natural Product Spiculoic Acid A
摘要:
[GRAPHIC]An enantioselective approach toward the recently isolated marine natural product, spiculoic acid A, conceptualized along the proposed biogenetic hypothesis, involving an intramolecular Diels-Alder reaction as the pivotal step, is delineated. Access to a structurally embellished bicyclic core of the natural product has been accomplished.
A new hexacyclic iboga-type indole alkaloid, voacangalactone (1), was isolatedfrom Voacanga africana, and its structure including the absolute configuration was established by asymmetric total synthesis involving such key steps as the asymmetric Diels–Alder reaction using an aminodiene and the construction of an isoquinuclidine ring and an indole skeleton.
The total synthesis of natural (+)-spiculoic acid A, a new cytotoxic marine natural product of polyketide origin, has been accomplished for the first time. The key step of the total synthesis was a stereciselective and high-yielding intramolecular Diels-Alder reaction of a highly functionalized (E,E,E)-2,7,9-dodecanal derivative for the construction of the core tetrahydroindan-2-one skeleton. (C) 2009 Elsevier Ltd. All rights reserved.