19270-26-9

Upstream product

• 123107-83-5 3,5-O-benzylideneerythronolide B 
• 114137-92-7 tert-Butyl-{(1R,2R)-1-ethyl-2-[(2S,4R,5R,6R)-2-(4-methoxy-phenyl)-5-methyl-6-((S)-1-methyl-2-phenylsulfanyl-ethyl)-[1,3]dioxan-4-yl]-propoxy}-diphenyl-silane 
• 123219-40-9 (2R,4R)-4-[(2R,4S,5S,6R)-6-[(1R,2R)-2-(tert-Butyl-diphenyl-silanyloxy)-1-methyl-butyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-2-[(4R,5S,6R)-2,2,5-trimethyl-6-((S)-1-methyl-allyl)-[1,3]dioxan-4-yl]-pentan-2-ol 
• 114114-43-1 (S)-3-[(2S,4R,5R,6R)-6-[(1R,2R)-2-(tert-Butyl-diphenyl-silanyloxy)-1-methyl-butyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-1,1,1-triphenyl-butan-2-one 
• 123219-39-6 (2S,3R,4S)-4-[(2S,4R,5R,6R)-6-[(1R,2R)-2-(tert-Butyl-diphenyl-silanyloxy)-1-methyl-butyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-3-phenylsulfanyl-2-[(4R,5S,6R)-2,2,5-trimethyl-6-((S)-1-methyl-allyl)-[1,3]dioxan-4-yl]-pentan-2-ol 
• 31521-14-9 8,9-anhydro-10-epi-erythronolide B 6,9-hemiketal 
• 3225-82-9 Erythronolide B 
• 114114-29-3 (2R,4R)-4-[(4S,5S,6S)-6-((1S,2R)-2-Hydroxy-1-methyl-butyl)-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-2-[(4R,5S,6R)-2,2,5-trimethyl-6-((S)-1-methyl-allyl)-[1,3]dioxan-4-yl]-pentan-2-ol 
• 114114-46-4 (R)-2-((4S,5S,6R)-6-{(1R,3R)-1-Hydroxy-3-[(4S,5S,6S)-6-((1S,2R)-2-hydroxy-1-methyl-butyl)-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-1-methyl-butyl}-2,2,5-trimethyl-[1,3]dioxan-4-yl)-propionic acid 
• 56014-68-7 (1S,2R,5R,6R,7R,8S,9S,10R,12R,13R,15R,17S)-5-Ethyl-7,9,12-trihydroxy-2,6,8,10,12,17-hexamethyl-15-phenyl-4,14,16-trioxa-bicyclo[11.3.1]heptadecan-3-one 
• 114137-93-8 (2S,3R,4S)-3-Benzenesulfinyl-4-[(2S,4R,5R,6R)-6-[(1R,2R)-2-(tert-butyl-diphenyl-silanyloxy)-1-methyl-butyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-2-[(4R,5S,6R)-2,2,5-trimethyl-6-((S)-1-methyl-allyl)-[1,3]dioxan-4-yl]-pentan-2-ol 
• 114114-45-3 {(1R,2R)-2-[(2S,4R,5R,6R)-6-[(S)-2-((R)-Benzenesulfinyl)-1-methyl-ethyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-1-ethyl-propoxy}-tert-butyl-diphenyl-silane 
• 114181-58-7 {(1R,2R)-2-[(2S,4R,5R,6R)-6-[(S)-2-((S)-Benzenesulfinyl)-1-methyl-ethyl]-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-1-ethyl-propoxy}-tert-butyl-diphenyl-silane 
• 114114-46-4 (R)-2-((4S,5S,6R)-6-{(1R,3R)-1-Hydroxy-3-[(2R,4S,5S,6S)-6-((1S,2R)-2-hydroxy-1-methyl-butyl)-2-(4-methoxy-phenyl)-5-methyl-[1,3]dioxan-4-yl]-1-methyl-butyl}-2,2,5-trimethyl-[1,3]dioxan-4-yl)-propionic acid 

Downstream Products

• 19270-26-9 10-epi-erythronolide B 
• 17867-92-4 O³,O⁵-phenylboranediyl-12-deoxy-erythronolide-A 

Relevant academic research and scientific papers

The Role of Serine-246 in Cytochrome P450eryF-Catalyzed Hydroxylation of 6-Deoxyerythronolide B

A strongly conserved threonine residue in the I-helix of cytochrome P450 enzymes participates in a proton delivery system for binding and cleavage of dioxygen molecules. 6-Deoxyerythronolide B hydroxylase (P450eryF) is unusual in that the conserved threonine residue is replaced by alanine in this enzyme. On the basis of crystal structures of substrate-bound P450eryF, it has been proposed that the C-5 hydroxyl group of the substrate and serine-246 of the enzyme form hydrogen bonds with water molecules 519 and 564, respectively. This hydrogen bonding network constitutes the proton delivery system whereby P450eryF maintains its catalytic activity in the absence of a threonine hydroxyl group in the conserved position. To further assess the role in the proton delivery system of hydroxyl groups around the active site, three mutant forms of P450eryF (A245S, S246A, and A245S/S246A) were constructed and characterized. In each case, decreased catalytic activity and increased uncoupling could be correlated with changes in the hydrogen bonding environment. These results suggest that Ser-246 does indeed participate in the proton shuttling pathway, and also support our previous hypothesis that the C-5 hydroxyl group of the substrate participates in the acid-catalyzed dioxygen bond cleavage reaction.

Frontiers and opportunities in chemoenzymatic synthesis

Natural product biosynthetic pathways have evolved enzymes with myriad activities that represent an expansive array of chemical transformations for constructing secondary metabolites. Recently, harnessing the biosynthetic potential of these enzymes through chemoenzymatic synthesis has provided a powerful tool that often rivals the most sophisticated methodologies in modern synthetic chemistry and provides new opportunities for accessing chemical diversity. Herein, we describe our research efforts with enzymes from a broad collection of biosynthetic systems, highlighting recent progress in this exciting field.

STEREO-CONTROLLED SYNTHESIS OF ERYTHRONOLIDES A AND B FROM 1,6-ANHYDRO-β-D-GLUCOPYRANOSE (LEVOGLUCOSAN). SKELETON ASSEMBLY IN (C9 - C13) + (C7 - C8) + (C1 - C6) SEQUENCE

Stereospecific syntheses of erythronolides A and B have been accomplished starting from 1,6-anhydro-β-D-glucopyranose (levoglucosan) in a uniform synthetic sequence.

TOTAL SYNTHESIS OF ERYTHRONOLIDE B. 1. SKELETON ASSEMBLY IN (C9-C13) + (C7-C8) + (C1-C6) SEQUENCE.

Erythronolide B has been synthesized starting from levoglucosan.

ACID-CATALYZED MODIFICATIONS OF ERYTHRONOLIDE A AND ERYTHRONOLIDE B. PREPARATION OF 9,10-ANHYDROERYTHRONOLIDE A AND B 6,9-HEMIKETALS

Treatment of erythronolide A (7) with glacial acetic acid afforded a mixture of 8,9-anhydroerythronolide A 6,9-hemiketal (9) and erythronolide A 6,9;9,11-spiroketal (11).Heating of the latter compound in aqueous pyridine yielded 9,10-anhydroerythronolide A 6,9-hemiketal (18).Erythronolide B (8) was converted to 9,10-anhydroerythronolide B 6,9-hemiketal (19) by analogous reaction.Evidence for the hemiketal structures 18 and 19 was obtained by means of their 1H-NMR spectra.The enol ether structure 19 was further confirmed by its conversion to 8,9-anhydro-10-epi-erythronolide B 6,9-hemiketal (20), followed by acid hydrolysis to 10-epi-erythronolide B (21).