26811-78-9

Upstream product

• 20316-32-9 ethyl 3-hydroxy-5-methyl-4-pentenoate 
• 123-73-9 trans-Crotonaldehyde 
• 64-19-7 acetic acid 
• 20316-32-9 3-hydroxy-hex-4-enoic acid ethyl ester 
• 1775-43-5 (Z)-3-hexenoic acid 
• 226067-49-8 N-[(2R,3S)-2-bromo-3-hydroxy-(E)-4-hexenoyl]-(1S,5R,7R)-10,10-dimethyl-3-thioxo-2-aza-4-oxatricyclo[6.2.1.0^1,5]decane 
• 158252-57-4 methyl (4E,3R)-3-hydroxy-4-hexenoate 
• 158252-55-2 ethyl (3R,4E)-3-hydroxy-4-hexenoate 
• 167259-97-4 N-<(R)-(E)-3-Hydroxy-4-hexenoyl>-(1S,5R,7R)-10,10-dimethyl-3-thioxo-2-aza-4-oxatricyclo<5.2.1.0^1,5>decane 
• 105-36-2 ethyl bromoacetate 
• 123-73-9 crotonaldehyde 
• 141-78-6 ethyl acetate 

Relevant academic research and scientific papers

Stereospecific Formation of E- and Z-Disubstituted Double Bonds by Dehydratase Domains from Modules 1 and 2 of the Fostriecin Polyketide Synthase

The dehydratase domain FosDH1 from module 1 of the fostriecin polyketide synthase (PKS) catalyzed the stereospecific interconversion of (3R)-3-hydroxybutyryl-FosACP1 (5) and (E)-2-butenoyl-FosACP1 (11), as established by a combination of direct LC-MS/MS and chiral GC-MS. FosDH1 did not act on either (3S)-3-hydroxybutyryl-FosACP1 (6) or (Z)-2-butenoyl-FosACP1 (12). FosKR2, the ketoreductase from module 2 of the fostriecin PKS that normally provides the natural substrate for FosDH2, was shown to catalyze the NADPH-dependent stereospecific reduction of 3-ketobutyryl-FosACP2 (23) to (3S)-3-hydroxybutyryl-FosACP2 (8). Consistent with this finding, FosDH2 catalyzed the interconversion of the corresponding triketide substrates (3R,4E)-3-hydroxy-4-hexenoyl-FosACP2 (18) and (2Z,4E)-2,4-hexadienoyl-FosACP2 (21). FosDH2 also catalyzed the stereospecific hydration of (Z)-2-butenoyl-FosACP2 (14) to (3S)-3-hydroxybutyryl-FosACP2 (8). Although incubation of FosDH2 with (3S)-3-hydroxybutyryl-FosACP2 (8) did not result in detectable accumulation of (Z)-2-butenoyl-FosACP2 (14), FosDH2 catalyzed the slow exchange of the 3-hydroxy group of 8 with [18O]-water. FosDH2 unexpectedly could also support the stereospecific interconversion of (3R)-3-hydroxybutyryl-FosACP2 (7) and (E)-2-butenoyl-FosACP2 (13).

The Mechanism of Dehydrating Bimodules in trans-Acyltransferase Polyketide Biosynthesis: A Showcase Study on Hepatoprotective Hangtaimycin

A bioassay-guided fractionation led to the isolation of hangtaimycin (HTM) from Streptomyces spectabilis CCTCC M2017417 and the discovery of its hepatoprotective properties. Structure elucidation by NMR suggested the need for a structural revision. A putative HTM degradation product was also isolated and its structure was confirmed by total synthesis. The biosynthetic gene cluster was identified and resembles a hybrid trans-AT PKS/NRPS biosynthetic machinery whose first PKS enzyme contains an internal dehydrating bimodule, which is usually found split in other trans-AT PKSs. The mechanisms of such dehydrating bimodules have often been proposed, but have never been deeply investigated. Here we present in vivo mutations and in vitro enzymatic experiments that give first and detailed mechanistic insights into catalysis by dehydrating bimodules.

Regioselectivity in the ene reaction of singlet oxygen with alkenes bearing an electron withdrawing group at β-position

Electronic repulsions between a perepoxide intermediate and the allylic functionality in the product forming transition state, direct the regioselectivity in the photooxygenation of trisubstituted alkenes bearing an electron withdrawing group at β-position.

New chiral acetate imide enolate for stereoselective aldol reactions

The chiral imide acetate 4 reacts upon lithium and titanium enolate formation conditions with aldehydes in a stereoselective manner. Remarkably, aldols obtained from aromatic and α,β-unsaturated aldehydes exhibited opposite stereochemistry than those obtained from aliphatic aldehydes.

Asymmetric Aldol Type Reactions of Acetate Imide Enolates

Titanium-mediated chelation-controlled aldol type reactions of acetate thioimide with representative aldehydes proceed with high ?-facial differentiation.An investigation of the influence of the nature of the imide enolate ligands and the Lewis acids in t

Enantioselective Aldol Type Reactions of Acetate Titanium Enolate with α,β-Unsaturated Aldehyde-TiCl4 Complex

The camphor-derived N-acetyloxazolidinethione has been used to effect enantioselective aldol type reaction of the derived thioimide titanium enolate with unsaturated aldehyde-TiCl4 complex.The observed facial selectivity is best explained by an open trans

An Unusual Enantioselective Aldol Type Reaction of Acetate Boryl Enolate Derived from Chiral Thioimide

The camphor-derived N-acetyloxazolidinethione has been used to effect enantioselective aldol type reactions of the derived 9-BBN enolate with a variety of aldehydes.Mechanistically, the observed facial selectivity is best explained by a boatlike transitio

Polyenic acids. II. Antifungal and bacteriostatic 4-bromo hexa-2,4 dienoic acids derivatives

Some structural modifications of the dienic chain of 2,4 (2 E, 4 E)-hexadienoic acid - functionalisation, cyclic integration, epoxydation - were investigated. Only ω-oxydation allowed gain in bacteriostatic activity without reducing fungistatic activity of the reference compound: esters 10, 11 and 19. The corresponding acids 10a and 11a show a slight drop in fungistatic activity.

STEREOSELECTIVE IODOLACTONIZATION OF ACYCLIC UNSATURATED 3-HYDROXYACIDS

A stereoselective method for preparing 3-hydroxy-4-alkyl-γ-lactones is reported.Iodolactonization of 3-hydroxy-4-alkenoic acids produces predominantly the thermodynamically less stable 3,4-cis products, which undergo methanolysis to threo-epoxyalcohols.