Systematic Construction of a Monotetrahydrofuran-Ring Library inAnnonaceous Acetogenins by Asymmetric Alkynylation and Stereodivergent Tetrahydrofuran-Ring Formation
diastereoisomers of the monotetrahydrofuran-ring cores of annonaceousacetogenins have been synthesized through utilization of asymmetric alkynylation and stereodivergent one-pot tetrahydrofuran-ring formation. In all cases, the asymmetric alkynylation proceeded with very high diastereoselectivity to give eight kinds of optically pure tetrahydrofuran core from a common alpha-oxyaldehyde. We also describe
Convergent total syntheses of murisolin (1), natural 16,19-cis-murisolin 2, and unnatural 16,19-cis-murisolin 3 were accomplished by asymmetric alkynylation of alpha-tetrahydrofuranic aldehyde with a diyne and Sonogashira coupling with a gamma-lactone segment as the key steps. Stereoisomers of alpha-tetrahydrofuranic aldehyde were synthesized with high optical purity and the asymmetric alkynylation
Systematic synthesis of bis-THF ringcores, synthetic intermediates of adjacent bis-THF annonaceousacetogenins, has been achieved by asymmetric alkynylation and subsequent stereodivergent THF ring formation. The asymmetric alkynylation of alpha-tetrahydrofuranic aldehyde with (S)-3-butyne-1,2-diol derivatives gave good yields of erythro- and threo-adducts with very high diastereoselectivity. These
The convergent synthesis of fluorescence-labeled solamin, an antitumor Annonaceous acetogenin, was accomplished by two asymmetric alkynylations of 2,5-diformyl tetrahydrofuran with an alkyne tagged with fluorescent groups and another alkyne with an alpha,beta-unsaturated gamma-lactone. Assay for the growth inhibitory activity against human cancer cell lines revealed that the probe with the fluorescent groups at the end of the hydrocarbon chain may have the same mode of action as natural acetogenins. The merged fluorescence of dansyl-labeled solamin and MitoTracker Red suggests that Annonaceous acetogenins localize in the mitochondria. (C) 2010 Elsevier Ltd. All rights reserved.