Starting from the glucose-derived d-lactone and the functionalized aryl bromide, the first total synthesis of naturally occurring paecilomycin B was achieved via functionalized aryl-beta-C-glycoside synthesis using 2,4,6-triisopropylphenyllithium under Barbier-type reaction conditions and ring-closing metathesis as the key steps.
Convergent Total Synthesis of Paecilomycin B and 6′-<i>epi</i>-Paecilomycin B by a Barbier-Type Reaction Using 2,4,6-Triisopropylphenyllithium
作者:Kiyomi Ohba、Masaya Nakata
DOI:10.1021/acs.joc.7b03041
日期:2018.7.6
The convergent total synthesis of the natural product paecilomycin B and its 6′-epimer was investigated. The aryl-C-glycoside skeleton was constructed by an intramolecular Barbier-type reactionusing 2,4,6-triisopropylphenyllithium and subsequent deoxygenation of the resulting anomeric hydroxy group. Starting from aryl iodide 24, the addition reaction afforded the thermodynamically stable C-β macrocyclic
Six new β-resorcylicacid lactones (1−6), named paecilomycins A−F, and five known compounds, aigilomycin B (7), zeaenol (8), aigialomycin D (9), aigialomycin F (10), and aigialospirol, were isolated from the mycelial solid culture of Paecilomyces sp. SC0924. Their structures were elucidated by extensive NMR analysis, single-crystal X-ray study, and chemical correlations. Compounds 5 and 10 exhibited