Development of a Multigram Asymmetric Synthesis of 2-(R)-2-(4, 7, 10-Tris tert-Butylcarboxymethyl-1, 4, 7, 10-tetraazacyclododec-1-yl)-pentanedioic Acid, 1-tert-Butyl …

…, SR Witowski, R Lombardy, K Koppetsch

Index: Levy, Stuart G.; Jacques, Vincent; Zhou, Kevin Li; Kalogeropoulos, Shirley; Schumacher, Kelly; Amedio, John C.; Scherer, Jonathan E.; Witowski, Steven R.; Lombardy, Richard; Koppetsch, Karsten Organic Process Research and Development, 2009 , vol. 13, # 3 p. 535 - 542

Full Text: HTML

Citation Number: 16

Abstract

A process for the multigram asymmetric synthesis of the chiral tetraazamacrocycle 2-(R)-2- (4, 7, 10-tris tert-butylcarboxymethyl-1, 4, 7, 10-tetraazacyclododec-1-yl)-pentanedioic acid, 1-tert-butyl ester ((R)-tert-Bu4-DOTAGA, 4) has been devised and demonstrated. The nine- step synthesis features an improved synthesis of 2-(S)-5-oxotetrahydrofuran-2-carboxylic acid, tert-butyl ester 8, the precursor to the novel alkylating agent (S)-5-benzyl 1-tert-butyl ...