4244-66-0Relevant academic research and scientific papers
The Synthesis of Structurally Diverse Macrocycles by Successive Ring Expansion
Kitsiou, Christiana,Hindes, Jordan J.,I'Anson, Phillip,Jackson, Paula,Wilson, Thomas C.,Daly, Eleanor K.,Felstead, Hannah R.,Hearnshaw, Peter,Unsworth, William P.
, p. 15794 - 15798 (2015)
Structurally diverse macrocycles and medium-sized rings (9-24 membered scaffolds, 22 examples) can be generated through a telescoped acylation/ring-expansion sequence, leading to the insertion of linear fragments into cyclic β-ketoesters without performin
Evaluating the Viability of Successive Ring-Expansions Based on Amino Acid and Hydroxyacid Side-Chain Insertion
Lawer, Aggie,Epton, Ryan G.,Stephens, Thomas C.,Palate, Kleopas Y.,Lodi, Mahendar,Marotte, Emilie,Lamb, Katie J.,Sangha, Jade K.,Lynam, Jason M.,Unsworth, William P.
supporting information, p. 12674 - 12683 (2020/09/17)
The outcome of ring-expansion reactions based on amino/hydroxyacid side-chain insertion is strongly dependent on ring size. This manuscript, which builds upon our previous work on Successive Ring Expansion (SuRE) methods, details efforts to better define the scope and limitations of these reactions on lactam and β-ketoester ring systems with respect to ring size and additional functionality. The synthetic results provide clear guidelines as to which substrate classes are more likely to be successful and are supported by computational results, using a density functional theory (DFT) approach. Calculating the relative Gibbs free energies of the three isomeric species that are formed reversibly during ring expansion enables the viability of new synthetic reactions to be correctly predicted in most cases. The new synthetic and computational results are expected to support the design of new lactam- and β-ketoester-based ring-expansion reactions.
Preparing method of 5,6-dihydro-2H-pyran-2-one
-
Paragraph 0024; 0025, (2019/10/02)
The invention relates to a new synthesis route of 5,6-dihydro-2H-pyran-2-one. 3-(benzyloxy)propionic acid is taken as a raw material, and through four steps of a chlorination reaction, a condensationreaction, a cyclization reduction reaction and an elimin
Iterative Assembly of Macrocyclic Lactones using Successive Ring Expansion Reactions
Stephens, Thomas C.,Lawer, Aggie,French, Thomas,Unsworth, William P.
supporting information, p. 13947 - 13953 (2018/09/14)
Macrocyclic lactones can be prepared from lactams and hydroxyacid derivatives via an efficient 3- or 4-atom iterative ring expansion protocol. The products can also be expanded using amino acid-based linear fragments, meaning that macrocycles with precise
Synthesis of Cyclic Peptide Mimetics by the Successive Ring Expansion of Lactams
Stephens, Thomas C.,Lodi, Mahendar,Steer, Andrew M.,Lin, Yun,Gill, Matthew T.,Unsworth, William P.
supporting information, p. 13314 - 13318 (2017/10/05)
A successive ring-expansion protocol is reported that enables the controlled insertion of natural and non-natural amino acid fragments into lactams. Amino acids can be installed into macrocycles via an operationally simple and scalable iterative procedure, without the need for high dilution. This method is expected to be of broad utility, especially for the synthesis of medicinally important cyclic peptide mimetics.
Synthesis of polycyclic benzofused nitrogen heterocycles via a tandem ynamide benzannulation/ring-closing metathesis strategy. Application in a formal total synthesis of (〈)-FR900482
Mak, Xiao Yin,Crombie, Aimee L.,Danheiser, Rick L.
experimental part, p. 1852 - 1873 (2011/06/17)
A two-stage "tandem strategy" for the synthesis of benzofused nitrogen heterocycles is described that is particularly useful for the construction of systems with a high level of substitution on the benzenoid ring. The first stage in the strategy involves
Aldol reactions between L-erythrulose derivatives and chiral α-amino and α-fluoro aldehydes: Competition between felkin-anh and cornforth transition states
Diaz-Oltra, Santiago,Carda, Miguel,Murga, Juan,Falomir, Eva,Marco, J. Alberto
supporting information; scheme or table, p. 9240 - 9254 (2009/09/30)
Both matched and mismatched diastereoselection have been observed in aldol reactions of a boron enolate of a protected L-erythrulose derivative with several chiral α-fluoro and α-amino aldehydes. Strict adherence to the Felkin-Anh model for the respective transition structures does not account satisfactorily for all the observed results, as previously observed in the case of α-oxygenated aldehydes. In some cases, only the Cornforth model provides a good explanation. The factors that influence this dichotomy are discussed and a general mechanistic model is proposed for aldol reactions with α-heteroatom-substituted aldehydes. Additional support for the model was obtained from density functional calculations.
2-SUBSTITUTED QUINAZOLIN-4-YLAMINE ANALOGUES AS CAPSAICIN RECEPTOR MODULATORS
-
Page 57-58, (2010/02/07)
Certain 2-substituted quinazolin-4-ylamine analogues are provided. Such compounds are ligands that may be used to modulate specific receptor activity in vivo or in vitro, and are particularly useful in the treatment of conditions associated with pathologi
Small ring constrained peptidomimetics. Synthesis of epoxy peptidomimetics, inhibitors of cysteine proteases
Demarcus,Ganadu,Mura,Porcheddu,Quaranta,Reginato,Taddei
, p. 697 - 706 (2007/10/03)
Different dipeptide analogues containing an oxirane ring in the place of the peptidic bond were prepared starting from naturally occurring amino acids. N-Fmoc-amino aldehydes were transformed into the corresponding methoxyvinyl derivatives through a Wittig reaction, and the addition of PhSeCl gave a series of different α-phenylselenyl aldehydes. Mukajiama reaction with silylketene acetals gave an intermediate product that was finally transformed into the desired oxiranyl peptidomimetics. Following this strategy we were able to control three new contiguous stereocenters starting from the enantiomerically pure amino acid. The dipeptide analogues could be used in SPPS on a SASRIN resin as the final epoxides were relatively unstable under acidic conditions. Moreover the synthesis of the single dipeptide mimetics was carried out on solid phase to generate a small library of epoxy peptidomimetics. Some of the products prepared in this work resulted as time-dependent reversible inhibitors of cysteine protease.
