A Convenient Synthesis of Novel Spiroisoindole γ-Halobutyrolactones via Halocyclization of γ-Ethylenic Acids
摘要:
gamma-Ethylenic carboxylic acids are cyclized to spirolsoindolone gamma-halomethylbutyrolactones, in the presence of NBS or NIS and K2CO3. The corresponding haloaspirobutyrolactones were isolated in high yields (57-95%).
Silver-catalyzed spirolactonization: first synthesis of spiroisoindole-γ-methylene-γ-butyrolactones
摘要:
gamma-Acetylenic carboxylic acids are cyclized to spirolactones under mild conditions, in the presence of Ag2CO3 catalyst. The corresponding spiro-5-alkylidene-gamma-butyrolactones were isolated in high yields, and this process constitutes an easy and efficient route to analogous structures of natural products of biological interest. (c) 2008 Elsevier Ltd. All rights reserved.