Funebrine, a structurally novel pyrrole alkaloid, and other .gamma.-hydroxyisoleucine-related metabolites of Quararibea funebris (Llave) Vischer (Bombacaceae)

Abstract

The flowers of the Mexican tree Quararibea funebris (Llave) Vischer (Bombacaceae) have been shown to give rise to the enolic 7-lactone 1, its amino analogue 3, the saturated lactone 4, and the parent amino acid (2S,3S,4R)-7-hydroxyisoleucine (5), as well as the novel pyrrole alkaloid funebrine (6). The structure determination of funebrine by X-ray crystallography is discussed and a hypothesis for its biogenesis offered.

Instrumental and Sensory Approaches for the Characterization of Compounds Responsible for Wine Aroma

“…This is in agreement with the relative acidity of this compound. High-resolution (HR) mass spectrometry confirmed our previous results, and, in view of the accuracy of the determinations, the fragment masses are completely in agreement with the suggested structure [25]. Moreover, the retention index of the reference compound was 2172 and 1066 for the FFAP and BP1 columns, respectively.…”

A Maillard Approach to 2‐Formylpyrroles: Synthesis of Magnolamide, Lobechine and Funebral

“…Our initial efforts were directed towards a facile asymmetric preparation of amino lactone 11 starting from known ketone 12 [17] (Scheme 4). Gratifyingly, a single diastereoisomer of the desired formylpyrrole adduct 24a was obtained in moderate yield along with TBS-protected condensation product funebrine 25a [21] and a small amount of unidentifiable decomposition products. CBS-mediated reduction of the ketone carbonyl subsequently provided a mixture of epimeric lactones 23a and 23b (dr 4:1) that were separable by careful column chromatography.…”

Recent applications of gallium and gallium halides as reagents in organic synthesis

“…75 The products 25 of this reaction are potential substrates for the synthesis of sotolone type natural products. 76 …”