Convenient Synthesis of Pulchella-lactam, a CD45 Protein Tyrosine Phosphatase Inhibitor from the Marine Fungus Corollospora pulchella, and Its Related Compounds
Synthesis of aminal-type Lilium candidum alkaloids and lilaline; determination of their relative configuration by the concerted use of NMR spectroscopy and DFT conformational analysis
作者:Sándor Nagy、Áron Szigetvári、Viktor Ilkei、Balázs Krámos、Zoltán Béni、Csaba Szántay、László Hazai
DOI:10.1016/j.tet.2020.131827
日期:2021.2
We hereby report the synthesis of six racemic alkaloids isolated from Lilium candidum L. Their common structural feature is a five-membered lactam ring which is, in the case of the flavonoid alkaloid lilaline, attached to the molecule’s aromatic core, while in the case of the other five compounds, it is connected to the nitrogen atom of a pyrrolinone ring by an aminal function. The syntheses of these
Convenient route to both enantiomers of chiral 5-hydroxypyrrolidin-2-one and 5-hydroxy-1,5-dihydropyrrol-2-one: reverse enantioselectivity in lipase-catalyzed kinetic resolution
作者:Kunihiko Takabe、Masahisa Suzuki、Toshiki Nishi、Masaomi Hiyoshi、Yasuaki Takamori、Hidemi Yoda、Nobuyuki Mase
DOI:10.1016/s0040-4039(00)01745-7
日期:2000.12
High enantioselectivity was achieved in the lipase-catalyzedkineticresolution of 5-hydroxypyrrolidin-2-one and 5-hydroxy-1,5-dihydropyrrol-2-one derivatives. Lipase PS and Novozym 435 were the successful catalysts (E=>1000). The acetylation of the N-protected 5-hydroxy-1,5-dihydropyrrol-2-one derivative gave the (R)-acetate with high enantioselectivity, while, without N-protection, the (S)-acetate
Studies on diazepines. XXIV Reactions of monocyclic 1H-1,3-diazepines. 2 Photo-sensitized oxygenation.
作者:JYOJI KURITA、HIROKAZU KOJIMA、TAKASHI TSUCHIYA
DOI:10.1248/cpb.34.4871
日期:——
The photo-sensitized oxygenation of monocyclic 1H-1, 3-diazepines (6) gave several fragment products (7-12). 3-Pyrrolin-2-one derivatives (7 and 8) and ethyl aminoformates (9 and 10) are assumed to originate from the initially formed 4, 7-endoperoxides (13), and vinylaminoformates (11 and 12) from the 4, 5-dioxetanes (14).
Jatropham, (R)-(-)-5-hydroxy-3-methyl-3-pyrrolin-2-one, is synthesized in three steps from citraconic anhydride. Highly regioselective reduction of citraconimide gives racemic jatropham in high yield. Kinetic resolution of racemic jatropham using lipase is also described. (C) 1999 Elsevier Science Ltd. All rights reserved.