205386-57-8Relevant articles and documents
A Bioinspired Synthesis of (±)-Rubrobramide, (±)-Flavipucine, and (±)-Isoflavipucine
Mizutani, Shoma,Komori, Kenta,Taniguchi, Tohru,Monde, Kenji,Kuramochi, Kouji,Tsubaki, Kazunori
, p. 9553 - 9556 (2016)
A biomimetic synthesis of naturally occurring lactams rubrobramide, flavipucine, and isoflavipucine is described. The key step is a regioselective Darzens reaction between isobutyl glyoxal and an α-bromo-β-ketoamide. The construction of the core tricyclic ring system of rubrobramide was achieved by a cascade reaction in a single step from an α,β-epoxy-γ-lactam. Furthermore, the absolute configuration of naturally occurring (+)-rubrobramide was determined by vibrational circular dichroism. (±)-Flavipucine and (±)-isoflavipucine were synthesized from an epoxyimide, which was prepared by reaction of isobutyl glyoxal with a protected α-bromo-β-ketoamide. Deprotection of the epoxyimide and formation of the pyridone ring gave (±)-flavipucine, which was converted into (±)-isoflavipucine by thermal isomerization.
Enantioselective total synthesis of (+)-rubrobramide, (+)-talaramide A, and (?)-berkeleyamide D by a skeletal diversification strategy
Tanaka, Kosaku,Kobayashi, Kenichi,Kogen, Hiroshi
supporting information, p. 9780 - 9783 (2021/09/30)
A unified synthesis of (+)-rubrobramide, (+)-talaramide A, and (?)-berkeleyamide D was achieved from the vinylogous esters by a skeletal diversification strategy based on regioselective 5-exoor 6-endocyclization. This report describes the first enantioselective total synthesis of (+)-rubrobramide and (+)-talaramide A. Additionally, synthetic spirocyclic lactam compounds, including (?)-berkeleyamide D, showed moderate inhibitory activity against amyloid-β aggregation for the potential treatment of Alzheimer's disease.
