Total Synthesis of Hygrolines and Pseudohygrolines
摘要:
A concise two-step synthesis of all four diastereoisomeric hygrolines ((-)-hygroline (1), (+)-hygroline (2), (-)-pseudohygroline (3), (+)-pseudohygroline (4)) has been developed based on the (-)-sparteine (5)- or (+)-sparteine surrogate 11-mediated enantioselective lithiation of N-Boc pyrrolidine (6), followed by reaction of the chiral anion with (S)- or (R)-propylene oxide. Reduction of the resulting N-Boc amino alcohols furnished hygrolines and pseudohygrolines in 30% to 56% overall yields with dr's > 95:5.
New synthesis of all the four isomers of 2-(2-hydroxypropyl)pyrrolidines via iterative asymmetric dihydroxylation to cause enantiomeric enhancement
作者:Hiroki Takahata、Minoru Kubota、Takefumi Momose
DOI:10.1016/s0957-4166(97)00348-0
日期:1997.8
Both enantiomers of 2-(2-propenyl)pyrrolidine 7 (75–84% ee), prepared via the asymmetricdihydroxylation (AD) of terminal olefin 5, underwent the second AD to provide all of the four stereoisomeric 2-(2-hydroxypropyl)pyrrolidines 8 with enantiomeric enhancement (>98% ee). An asymmetricsynthesis, starting from 8, of several 2-(2-hydroxypropyl)pyrrolidine alkaloids is demonstrated.
Synthese des Hygrolins. Zur Stereochemie des Hygrins und Cuskhygrins
作者:F. Galinovsky、H. Zuber
DOI:10.1007/bf00902780
日期:——
An enantioselective synthesis of (+)-hygroline and (+)-pseudohygroline via Keck allylation and CBS reduction
作者:Shubhangi P. Bhoite、Rohit B. Kamble、Gurunath M. Suryavanshi
DOI:10.1016/j.tetlet.2015.06.012
日期:2015.8
An enantioselective synthesis of (+)-hygroline and (+)-pseudohygroline has been achieved in high optical purity (98% ee) from readily available 1,4-butanediol. The synthesis strategy employs a Keck allylation, CBS reduction, and Wacker oxidation. (C) 2015 Elsevier Ltd. All rights reserved.