Synthesis of Erythrochelin : A Hydroxamate-Type Siderophore from Saccharopolyspora erythraea

Erythrochelin, a hydroxamate-type siderophore produced by Saccharopolyspora erythraea, is synthesized for the first time. A key building block of erythrochelin containing the 2,5-diketopiperazine ring is prepared by intramolecular cyclization of the corresponding dipeptide precursor derived from two kinds of protected δ-N-hydroxy-L-ornithines. Consecutive condensation of the building block with protected D-serine and protected δ-N-hydroxy-D-ornithine, followed by deprotection, furnishes erythrochelin

Synthesis of Fluorine-Containing Analogues of 1-Lysoglycerophospholipids via Horner–Wadsworth–Emmons Reaction

This article describes an efficient method of synthesizing fluorine-containing analogues of 1-lysoglycerophospholipids (1-LPLs) by introducing a palmitoyl moiety starting from bis(2,2,2-trifluoroethyl)phosphonoacetate (Still-Gennari reagent). Our method effectively employs Horner-Wadsworth-Emmons reagents as masked 1-LPL derivatives to prepare a series of analogues of 1-lysophosphatidic acid (1-LPA), 1-lysophosphatidylethanolamine (1-LPE), and 1-lysophosphatidylcholine (1-LPC)

Enzymatic synthesis of chiral P-stereogenic phosphonoacetates

In this data article, we describe the enzymatic kinetic resolution of a series of racemic mixed phosphonoacetates, which were successfully prepared from methyl bis(2,2,2-trifluoroethyl)phosphonoacetate (Still-Gennari reagent) by alcoholysis with σ-symmetrical secondary alcohols in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Porcine liver esterase (PLE)-catalyzed kinetic resolution of some of these racemic mixed phosphonoacetates proceeded in a highly stereoselective manner to furnish the chiral P-stereogenic phosphonoacetates (up to >99% ee)

Synthesis of Novel Phosphorus-Substituted Stable Isoindoles by a Three-Component Coupling Reaction of ortho-Phthalaldehyde, 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-Oxide, and Primary Amines

A three-component coupling reaction of ortho-phthalaldehyde, 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide, and various primary amines readily afforded novel phosphorus-substituted stable isoindoles in good to excellent yields. The importance of the reversible ring-opening of 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide by methanolysis in the three-component coupling reaction became apparent

Synthesis of Sterically Protected Isoindoles from ortho-Phthalaldehyde

o-Phthalaldehyde (OPA) reacts with O-protected tris(hydroxyalkyl) aminomethanes in the presence of 1-propanethiol to afford a novel class of stable isoindoles. Steric protection provided by the bulkiness of C3-symmetric primary amines derived from tris(hydroxymethyl)aminomethane could be significant for the stabilization of 1-alkylthio-2-alkyl-substituted isoindoles derived from OPA. A plausible reaction mechanism is proposed to explain the formation of the isoindole and an isoindolin-1-one by-product

EFFICIENT ONE-POT, THREE-STEP SYNTHESIS OF 1,2,3,5-TETRASUBSTITUTED PYRROLES VIA AZA-MICHAEL ADDITION OF METHYL 3-IMINOACRYLATES

An efficient one-pot, three-step procedure for the aza-Michael addition of methyl 3-iminoacrylates with secondary amines followed by intramolecular cyclization and silylation successfully afforded novel 1,2,3,5-tetrasubstituted pyrroles in high yields

ASYMMETRIC SYNTHESIS OF cis-4a,5,8,8a-TETRAHYDROPHTHALAZIN-1(2H)-ONE DERIVATIVES BASED ON ORGANOCATALYTIC ALCOHOLYSIS OF CYCLIC DICARBOXYLIC ANHYDRIDE

Asymmetric synthesis of optically active cis-4-phenyl-4a,5,8,8a-tetrahydrophthalazin-1(2H)-one and its N-alkylated derivatives based on an organocatalytic enantioselective alcoholysis of cyclic dicarboxylic anhydride was described

SYNTHESIS Of NOVEL 2,3-DISUBSTITUTED THIOPHENES VIA TANDEM THIA-MICHAEL/ALDOL REACTION Of ALLENYL ESTERS

A tandem thia-Michael/aldol reaction of allenyl esters and mercaptoacetaldehyde in the presence of triethylamine provided 2,3,4-trisubstituted tetrahydrothiophenes. Novel 2,3-disubstituted thiophenes were obtained in high yield by the subsequent dehydration of the 2,3,4-trisubstituted tetrahydrothiophenes using p-toluenesulfonic acid monohydrate as an effective catalyst