Total Syntheses of Anti-HIV Cyclodepsipeptides Aetheramides A and B

Abstract

A concise total synthesis of aetheramide A in an overall yield of 4.7% with a longest linear sequence of 15 steps is described. This synthetic strategy features macrocyclization via an intramolecular trapping of acylketene generated from dioxinone precursor, and stereoselective late-stage methylation of β-ketoamide. Aetheramide B could be synthesized via the ester migration of aetheramide A.

A Unified Synthetic Approach to Optically Pure Curvularin-Type Metabolites

“…Compounds 12b–12f were hydrogenated and further deprotected to provide sumalactones A–D ( 3 – 6 ), analogue 7 , analogue 8 , and xestodecalactone ( 9 ). Analogues 7 and 8 were the immigration products of sumalactone A ( 3 ) and D ( 6 ) . The analytical data of synthesized curvularin ( 1 ), dehydrocurvularin ( 2 ), sumalactones A–D ( 3 – 6 ), and xestodecalactone ( 9 ) was in full agreement with the reported values of these natural products.…”

Enantioselective syn- and anti-Alkoxyallylation of Aldehydes via Brønsted Acid Catalysis

“…The syn -alkoxyallylation adduct ent - 2a was used as the starting material for the synthesis of the C 1–7 fragment of natural product, aetheramide A (Scheme ). First, the methoxymethyl ether (MOM group) of ent - 2a was deprotected under acidic conditions to give diol 10 . In the presence of 10 mol % of Hoveyda-Grubbs second generation catalyst, cross-metathesis of 10 with acrolein generated aldehyde 11 .…”

Solid-state conformations of linear depsipeptide amides with an alternating sequence of α,α-disubstituted α-amino acid and α-hydroxy acid

“…In particular, cyclic depsipeptides are still of broad chemical, biological and medicinal interest, which is reflected in a large number of recent review articles [e.g. structure and isolation (Wang et al, 2018;Ding et al, 2016;Tarsis et al, 2015;Pelay-Gimeno et al, 2013), synthesis (Kö cher et al, 2017;Qi et al, 2016;Boecker et al, 2016;Weiss et al, 2013;Xu et al, 2013) and biological activity (Wang et al, 2018;Weiss et al, 2017;Kitagaki et al, 2015;Sivanathan & Scherkenbeck, 2014;Smelcerovic et al, 2014)]. Their general structures can be assigned to different classes, containing, besides -amino acids, a simple hydroxy acid, like in solonamide A (Kitir et al 2014), or a complex hydroxy acid, as in calcaripeptide A (Silber et al, 2013), being characterized by a head-to-side-chain lactonization, as in kahalalide A (Bourel-Bonnet et al, 2005), or with an alternating sequence of -amino and -hydroxy acids.…”