Highly Diastereoselective Epimerization: Stereodivergent Synthesis of α-Hydroxy-β-amino Isopentanoic Acid
摘要:
The high diastereoselectivity of the base-catalyzed epimerization of oxazolidin-2- ones 7 and 8 is shown to depend on the nature of the N-substituent (R group); when R = Bn, the 4,5-trans-product (4S,5R)-9 is formed, whereas when R = H the 4,5-cis-product (4S,5S)-10 is formed, both with > 99:1 dr. The successful hydrolysis of the oxazolidin-2-one group in both cis- and trans-derivatives show this to be a stereodivergent route to enantiopure alpha-hydroxy-beta-amino isopentanoic acids (2R,3S)-1 and (2S,3S)-2.
PYRUVAMIDE COMPOUNDS AS INHIBITORS OF DUST MITE GROUP 1 PEPTIDASE ALLERGEN
申请人:St. George's Hospital Medical School
公开号:EP2526116B1
公开(公告)日:2015-05-13
Highly Diastereoselective Epimerization: Stereodivergent Synthesis of α-Hydroxy-β-amino Isopentanoic Acid
作者:Woo Duck Seo、Marcus J. Curtis-Long、Young Bae Ryu、Jin Hwan Lee、Min Suk Yang、Woo Song Lee、Ki Hun Park
DOI:10.1021/jo060309m
日期:2006.6.1
The high diastereoselectivity of the base-catalyzed epimerization of oxazolidin-2- ones 7 and 8 is shown to depend on the nature of the N-substituent (R group); when R = Bn, the 4,5-trans-product (4S,5R)-9 is formed, whereas when R = H the 4,5-cis-product (4S,5S)-10 is formed, both with > 99:1 dr. The successful hydrolysis of the oxazolidin-2-one group in both cis- and trans-derivatives show this to be a stereodivergent route to enantiopure alpha-hydroxy-beta-amino isopentanoic acids (2R,3S)-1 and (2S,3S)-2.
Improved Stereoselectivity in Intramolecular S<sub>N</sub>2′ Cyclization through Use of Mechanistic Principles
作者:Ki Park、Woo Seo、Marcus Curtis-Long、Seong Jeong、Tae Jun、Min Yang
DOI:10.1055/s-2006-958956
日期:2007.1
Valine and alanine were converted into the corresponding α-hydroxy-β-amino acids through intramolecular S N 2' cyclization. The novel cyclization protocol relied upon the use of N-benzyl-protected carbamates derived from α-amino acids.