3 results for Allen, PA

  • Synthesis of C-2 functionalised 1,6,8-trioxadispiro[4.1.5.3]pentadec-13-enes

    Allen, PA; Brimble, Margaret; Fares, FA (1998)

    Journal article
    The University of Auckland Library

    The syntheses of bis-spiroacetals 28 and 44, model systems for the tricyclic bis-spiroacetal moiety of the polyether antibiotic epi-17-deoxy-(O-8)-salinomycin 3, are described. Introduction of an aldehyde group at C-2 was necessary for further elaboration of the right hand side of the molecule. It was found that the choice of protecting group on the hydroxymethyl substituent (precursor to an aldehyde group) was crucial to the outcome of the key oxidative cyclisation.

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  • Synthetic studies towards the B,C,D,E fragment of antibiotic CP44, 161

    Allen, PA; Brimble, Margaret; Prabaharan, H (1999)

    Journal article
    The University of Auckland Library

    The synthesis of polyethers 32 and 33 from tricyclic bis-spiroacetal aldehyde 27 and E-bromide 7 are described. A key step in the synthetic strategy involved the oxidative cyclisation of a bicyclic hydroxyspiroacetal 22a,b to a cis bis-spiroacetal un

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  • Synthesis of the bis-spiroacetal moiety of the polyether antibiotic CP44,161

    Allen, PA; Brimble, MA; Prabaharan, H (2001)

    Journal article
    The University of Auckland Library

    The syntheses of bis-spiroacetals 25a, 25c and 40 which constitute the central framework of the polyether antibiotic CP44,161 4, are described. The tricyclic bis-spiroacetal ring is formed by oxidative cyclisation of hydroxyspiroacetal 9 which in tur

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