Tandem double-intramolecular [4+2]/[3+2] cycloadditions of nitroalkenes. Studies toward a total synthesis of daphnilactone B: Piperidine ring construction

Scott E Denmark, Ramil Y. Baiazitov

Research output: Contribution to journalArticle

Abstract

Two model studies in support of a total synthesis of the complex polycyclic alkaloid daphnilactone B have been completed. The objectives of the models studies were to demonstrate the use of a tandem double-intramolecular [4+2]/[3+2] nitroalkene cycloaddition for the stereocontrolled construction of four of the rings in the core of the natural product. The first model study established the ability to create a pyrrolidine ring corresponding to ring A of daphnilactone B through a modification of the dipolarophile and subsequent functional group manipulations. The second model study required the modification of the dienophile in the [4+2] cycloaddition to accommodate the formation of a piperidine ring (ring B of daphnilactone B). Nitroalkene 26 containing a diene as the dienophile served well in the tandem cycloaddition to afford the nitroso acetal 38a in 77% yield. Subsequent functional group manipulations allowed for the high-yielding conversion to the core of daphnilactone B.

Original languageEnglish (US)
Pages (from-to)593-605
Number of pages13
JournalJournal of Organic Chemistry
Volume71
Issue number2
DOIs
StatePublished - Jan 20 2006

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ASJC Scopus subject areas

  • Organic Chemistry

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