Polyhydroxylated pyrrolizidines. Part 6: A new and concise stereoselective synthesis of (+)-casuarine and its 6,7-diepi isomer, from DMDP
摘要:
A new synthesis for (+)-casuarine (1) and its 6,7-diepi isomer (15) in a stereocontrolled manner, is reported herein. All appropriately protected polyhydroxylated pyrrolidine, such as (2R,3R,4R,5R)-3,4-dibenzyloxy-2'-O-tet-t-butyldiphenylsilyl-2,5-bis(hydroxymethl)pyrrolidine (3, protected DMDP), easily available from D-fructose, was chosen as the chiral starting material. Compounds 1 and 15 were obtained from 3, in seven steps, in a 23.2 and 20.5% overall yields, respectively. (c) 2005 Elsevier Ltd. All rights reserved.
[EN] SYNTHESIS OF POLYHYDROXYLATED ALKALOIDS<br/>[FR] SYNTHÈSE DES ALCALOÏDES POLYHYDROXYLÉS
申请人:MNL PHARMA LTD
公开号:WO2006008493A1
公开(公告)日:2006-01-26
A process for the production of a polyhydroxylated bicyclic (e.g. pyrrolizidine such as casuarine (10), indolizidine or quinolizidine) alkaloid comprises the cyclisation of a pyrrolidine or piperidine intermediate having three or more free hydroxyl groups.
Total Synthesis of Uniflorine A, Casuarine, Australine, 3-<i>epi</i>-Australine, and 3,7-Di-<i>epi</i>-australine from a Common Precursor
作者:Thunwadee Ritthiwigrom、Anthony C. Willis、Stephen G. Pyne
DOI:10.1021/jo902355p
日期:2010.2.5
A flexible method for the diastereoselective totalsynthesis of the pyrrolizidine alkaloids uniflorine A, casuarine, australine, and 3-epi-australine and the unnatural epimer 3,7-di-epi-australine from a common chiral 2,5-dihydropyrrole precursor is described.
[EN] TYROSINE LIGATION PROCESS<br/>[FR] PROCÉDÉ DE LIGATURE DE LA TYROSINE
申请人:NOVARTIS AG
公开号:WO2013009564A1
公开(公告)日:2013-01-17
A process is provided for preparing a conjugate of Formula (I-A) or (I) comprising a polypeptide (or a protein) containing n number of tyrosine units, where n is an integer greater than or equal to 1, dispersed within the amino acid chain having an amino terminus end (A1) and an acid terminus end (A2) of the protein or polypeptide (either the amino or acid terminus end can be the at least one tyrosine unit) and having a weight average molecular weight equal to or greater than 10,000 Daltons (10 kDa), wherein the conjugate comprises a number m of tyrosine conjugates (modified tyrosine residues) as depicted in Formula (I-A) or (I), where m is at least one and is less than or equal to n: where X, Lg, L and R are as defined herein.
Stereocomplementary synthesis of casuarine and its 6-<i>epi</i>-, 7-<i>epi</i>-, and 6,7-di<i>epi</i>-stereoisomers
作者:Yi-Xian Li、Jun-Zhe Wang、Atsushi Kato、Yuna Shimadate、Maki Kise、Yue-Mei Jia、George W. J. Fleet、Chu-Yi Yu
DOI:10.1039/d1ob01725j
日期:——
A stereocomplementary strategy allows the efficient synthesis of casuarine, 6-epi-casuarine, 7-epi-casuarine, and 6,7-diepi-casuarine from a cyclic nitrone and a nitrone-derived aldehyde. Their glycosidase inhibition profiles were compared.
Total Syntheses of Casuarine and Its 6-<i>O</i>-α-Glucoside: Complementary Inhibition towards Glycoside Hydrolases of the GH31 and GH37 Families
作者:Francesca Cardona、Camilla Parmeggiani、Enrico Faggi、Claudia Bonaccini、Paola Gratteri、Lyann Sim、Tracey M. Gloster、Shirley Roberts、Gideon J. Davies、David R. Rose、Andrea Goti
DOI:10.1002/chem.200801578
日期:2009.2.2
Selective glucosylation: Total synthesis of naturally occurring casuarine (1) and the first total synthesis of casuarine 6‐O‐α‐glucoside (2) were achieved through complete stereoselective nitrone cycloaddition, Tamao–Fleming oxidation and selective α‐glucosylation as key steps. Biological assays of the two compounds proved their strong and selective inhibitory properties towards glucoamylase NtMGAM and
选择性糖基化:通过完全立体选择性硝酮环加成,TAMao-Fleming氧化和选择性α-葡萄糖基化为关键步骤,实现了天然木麻黄的全合成(1)和木麻黄的6 - O -α-葡萄糖苷的首次全合成(2)。两种化合物的生物学分析证明它们分别对葡糖淀粉酶NtMGAM和海藻糖酶Tre37A具有强大的选择性抑制特性,这使它们成为这些酶的最强抑制剂。