74568-05-1Relevant articles and documents
Stereochemical elucidation of streptorubin B
Haynes, Stuart W.,Sydor, Paulina K.,Corre, Christophe,Song, Lijiang,Challis, Gregory L.
, p. 1793 - 1798 (2011/04/12)
Streptorubin B is a structurally remarkable mem-ber of the prodiginine group of antibiotics produced by several actinobacteria, including the model organism Streptomyces coelicolor A3(2). Transannular strain within the pyrrolophane structure of this molecule causes restricted rotation that gives rise to the possibility of (diastereomeric) atropisomers. Neither the relative nor the absolute stereochemistry of streptorubin B is known. NOESY NMR experiments were used to define the relative stereochemistry of the major atropisomer of streptorubin BHCl in solution as anti. We exploited this finding together with our knowledge of streptorubin B biosynthesis in S. coelicolor to determine the absolute stereochemistry of the anti atropisomer. 2-Undecylpyrrole stereoselectively labeled with deuterium at C-4′ was synthesized and fed to a mutant of S. coelicolor, which was unable to produce streptorubin B because it was blocked in 2-undecylpyrrole biosynthesis, and in which the genes responsible for the last two steps of streptorubin B biosynthesis were overexpressed. 1H and 2H NMR analysis of the stereoselectively deuterium-labeled streptorubin BHCl produced by this mutasynthesis strategy allowed us to assign the absolute stereochemistry of the major (anti) atropisomer as 7′S. HPLC analyses of streptorubin B isolated from S. coelicolor on a homochiral stationary phase and comparisons with streptorubin B derived from an enantioselective synthesis showed that the natural product consists of an approximately 88:7:5 mixture of the (7′S, anti), (7′S, syn), and (7′R, anti) stereoisomers.
Synthesis of (S)-γ- lactones with a combination of lipase-catalyzed resolution and mitsunobu reaction
Shimotori, Yasutaka,Miyakoshi, Tetsuo
experimental part, p. 1570 - 1582 (2009/11/30)
Six kinds of (S) - lactones [e.g., (S) - decalactone, (S) - undecalactone, and (S) - jasmolactone] were synthesized with 71-88% yields and 97% optical purities by combining lipase-catalyzed resolution with the Mitsunobu reaction. Copyright Taylor & Francis Group, LLC.
Facile synthesis of optically active γ-lactones via lipase-catalyzed reaction of 4-substituted 4-hydroxybutyramides
Matsumura, Yasufumi,Endo, Teruko,Chiba, Mitsuo,Fukawa, Hidemichi,Terao, Yoshiyasu
, p. 304 - 305 (2007/10/03)
Lipase-catalyzed transesterification of racemic 4-substituted 4- hydroxybutyramides with succinic anhydride proceeded enantioselectively to afford (S)-succinic acid monoester and unreacted (R)-4-hydroxybutyramide derivative, which were separated easily by