Formal syntheses of (−)-isoretronecanol, (+)-laburnine, and a concise enantioselective synthesis of (+)-turneforcidine
作者:Yu-Fu Liang、Chuang-Chung Chung、Meng-Wen Huang、Biing-Jiun Uang
DOI:10.1038/s41429-019-0169-9
日期:2019.6
Michael addition reaction of iminoglycinate 7 to ethyl γ-silyloxycrotonate with >98:<2 diastereoselectivity followed by hydrolysis and lactamization. Formal syntheses of (-)-isoretronecanol and (+)-laburnine as well as a concise enantioselective synthesis of (+)-turneforcidine could be achieved from functionalized pyroglutamates 15 or 16.
Stereodivergent Synthesis of 1-Hydroxymethylpyrrolizidine Alkaloids
作者:Abhijeet M. Sarkale、Chandrakumar Appayee
DOI:10.1021/acs.orglett.0c01375
日期:2020.6.5
stereodivergent strategy for the asymmetric synthesis of all stereoisomers of 1-hydroxymethylpyrrolizidine alkaloids is developed using an asymmetric self-Mannich reaction as a key step. An anti-selective self-Mannich reaction of methyl 4-oxobutanoate with the PMP-amine catalyzed by a chiral secondary amine is successfully optimized for the asymmetric synthesis of (+)-isoretronecanol and (−)-isoretronecanol
Highly Efficient and Stereoselective Radical Addition of Tertiary Amines to Electron-Deficient Alkenes − Application to the Enantioselective Synthesis of Necine Bases
作者:Samuel Bertrand、Norbert Hoffmann、Jean-Pierre Pete