The one-pot MAC (Masked Acyl Cyanide) reaction is used to perform the tandem oxyhomologation of N,N-dibenzyl-l-phenylalaninal and coupling with nitrogen nucleophiles provide a wide selection amide peptide derivatives (2S,3S)-allophenylnorstatin in generally good yields high anti selectivity, often dr >98:2. procedure works equally well other selected N,N-dibenzyl α-amino aldehydes, achieve very short synthesis (2S,3S,S)-epibestatin.

Using Garner's aldehyde as a substrate, one-pot MAC hydroxyhomologation reactions proceeded in good yields and with anti selectivity for the first time (dr up to 9:1). The products were used prepare panel of protected derivatives erythro-β-hydroxyaspartic acid erythro-β-hydroxyasparagine single enantiomers few steps.

A number of cyclic derivatives 3-amino-2,4-dihydroxybutanoic acid are known in the literature but they often prepared from other precursors. This study showed that title compound too may serve as a convenient substrate for cyclization reactions. Using orthogonally-protected linear derivatives, regioselective cyclizations were performed, leading to original and highly-functionalized γ-lactones, oxazolidinones, oxazolines aziridines. In these reactions key role was played by C3 nitrogen group...

The three-component reaction between a protected α-amino aldehyde, an alcohol and α-silyloxymalononitrile provides expedient access to α-hydroxy-β-amino acid derivatives. prototypical process, performed on N-Cbz-phenylalaninal, is known proceed with syn diastereoselectivity. present study demonstrates that the diastereoselectivity of can be inverted, using rationale Felkin-Anh interaction model. Reactions N,N-dibenzyl-L-phenylalaninal high anti diastereoselectivity, providing panel...

Hydrolysis of 1-substituted 7-oxanorborna-2,5-diene-2,3-dicarboxylates occurred regioselectively at the ester group in 3-position to give monocarboxylic acids from which diesters containing two different alkoxy groups and amido esters were selectively prepared. Hydrogenation these oxanorbornadiene derivatives followed by a retro-Diels–Alder reaction gave corresponding furans as single regioisomers.

Using O -pivaloyl protected D-galactopyranosylamine and D-arabinopyranosylamine, ( S ) or R configured α-substituted homoallylamines are synthesized with high diastereoselectivity by reaction of the corresponding aldimines allyltributylstannane. Electrophile-induced endo -trig-cyclization these N -glycosylhomoallylamines gave 2-substituted pyrrolidines diastereomeric purity.

Michael addition of heteroatom-and carbon-centered nucleophiles on 7-oxanorborna-2,5-diene-2-carboxaldehyde derivatives followed by a retro-Diels-Alder reaction allowed liquid-and solidphase synthesis small library α,β-unsaturated aldehydes.Emphasis should be put the purity enals prepared solid support, purification step was not necessary.

A modified version of the IMPACT heteronuclear multiple bond correlation (HMBC) has allowed characterization an organosilane and a tetrasilylated yttrium complex. With help this sequence, average gain in sensitivity close to 2 been obtained compared with standard HMBC experiment for disilanes as well complexes containing silylated ligands. This long‐range opens way following kinetics range fraction minute study by NMR low concentrated samples abundant nuclei. Copyright © 2013 John Wiley...

Abstract A chiral 1‐isopropenyl‐1‐(3‐oxopropyl)disilane derivative undergoes a type II ene reaction under Lewis acid catalyzed conditions to afford the silacyclic compound and an unexpected rearranged product with high diastereoselectivities. This rearrangement occurs through 1,2‐migration of trimethylsilyl group. common intermediate was proposed explain formation both products.

N-Lithiated azomethine ylides generated from N-arylidene-α-amino esters react on their Cγ:-atom with a 7-oxabicyclo[2.2.1]heptadiene derived diester. This regio- and stereoselective Michael addition yields β-amino diesters after acidic work-up. Retro-Diels-Alder reaction these amines or related amides allows the preparation of (aminomethyl)maleate derivatives. Keywords: Azomethine ylides, N-arylidene-a-amino esters, 1,3-dipolar cycloaddition, addition, retro-Diels-Alder

Abstract N 1 ‐substituted derivatives of anti ‐(2 R ,3 S )‐1,3‐diamino‐4‐phenylbutan‐2‐ol are important building blocks for the synthesis therapeutically molecules. We describe a simple protocol that allows transformation N,N ‐dibenzyl‐L‐phenylalaninal into such compounds in only two steps. The first step is fully stereoselective three‐component MAC (Masked Acyl Cyanide) oxyhomologation reaction implicating different amines to give panel ten ‐dibenzyl‐ O ‐ tert ‐butyldimethylsilyl‐protected...

A new preparation of 3-pyrrolines is described by [3+2] cycloadditions N-metalated azomethine ylides derived from α-amino esters with a dimethyl 7-oxabicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylate derivative, followed retro-Diels-Alder reactions. This two-step sequence appears superior to the direct reaction acetylenedicarboxylate and should be applicable solid-phase synthesis.

Abstract The intramolecular ene reaction of compound (I) gives the expected product (II) and also unexpected one (III) with high diastereoselectivity.

Abstract Symmetrical acetylene dicarboxylates undergo an unexpected highly selective mono‐transesterification with various alcohols in the presence of Candida rugosa lipase.

Abstract A convenient approach to furan derivatives is achieved through regioselective hydrolysis of Diels—Alder adducts (III), formation diesters or amido esters, hydrogenation, and retro‐Diels—Alder reaction.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at glance that was extracted from about 200 leading journals. To access Abstract, please click on HTML or PDF.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at glance that was extracted from about 200 leading journals. To access Abstract, please click on HTML or PDF.

Abstract ChemInform is a weekly Abstracting Service, delivering concise information at glance that was extracted from about 100 leading journals. To access of an article which published elsewhere, please select “Full Text” option. The original trackable via the “References”