Systematic Synthesis of Diastereomeric THF Ring Cores and Total Synthesis of Anti-Tumor Annonaceous Acetogenins

Abstract

We have developed a systematic synthesis of the poly-THF ring cores of anti-tumor Annonaceous acetogenins by utilizing asymmetric alkynylation and subsequent stereodivergent THF ring formation as key steps. The asymmetric alkynylation of α-oxyaldehyde and α-tetrahydrofuranic aldehyde with an (S)-3-butyne-1,2-diol derivative proceeded in good yield with very high diastereo­selectivity. These adducts were converted into mono- and bis-THF cores by two different methods involving one-pot THF ring formation. The total syntheses of murisolin, 16,19-cis-murisolin, and longimicin D, which show cytotoxic activity against the human ­tumor cell, were accomplished by applying this methodology.