From 1-(Silyloxy)Butadiene to 4-Amino-4-Deoxy-DL-Erythrose and to 1-Amino-1-Deoxy-DL-Erythritol Derivativesvia Hetero-Diels-Alder Reactions with Acylnitroso Dienophiles
作者:Albert Defoin、Joaquim Pires、Jacques Streith
DOI:10.1002/hlca.19910740806
日期:1991.12.11
Acylnitrosodienophiles 4 reacted instantly with 1-(silyloxy)butadiene 5α and led in good yield to the regioisomeric cycloadducts 6 (major) and 7 (minor; Scheme 2, Table 1). cis-Hydroxylation of these primary cycloadducts with OsO4 (catalyst) occurred stereospecifically and in high yield (8 and 9, resp.; Scheme 2). It was followed by reductive ring cleavage to give either 1-amino-1-deoxy-DL-erythritol
Asymmetric Diels-Alder reaction of the N-dienyl-L-pyroglutamic esters 1a-h with acyl nitroso dienophiles 4a-h gave diastereoisomeric adducts 6a-n, 7a-n with 12–90 % de, depending on solvents and temperature. An interpretation was gived. The “allylic effect” ( MO interactions) was found to be effective to account for the conformations of the adducts.
We report herein a strategy to afford a multicomponent catalyticenantioselectivesynthesis of β-substituted isoxazolidin-5-ones via a KMC process promoted by a suited cupreine used as bifunctional organocatalyst. The hydroxamic acid component, with a sterically hindered amide moiety, proved to be key for the successful formation and transformation of the obtained original N-amide isoxazolidin-5-ones
Darstellung und Acylierungen von 1.1-Dialkyl-3-hydroxyharnstoffen
作者:G. Zinner、G. Isensee
DOI:10.1002/ardp.19743070104
日期:——
Aus Hydroxylamin und den betreffenden Dialkylcarbomoylchloriden wurden 1.1‐Dimethyl‐und 1.1‐Diäthyl‐3‐hydroxyharnstoff sowie N.O‐Bis(dimethylcarbamoyl)‐hydroxylamin erhalten und in weitere Acylierungsreaktionen mit Isocyansäureestern, Chlorameisensäuremethylester und Säurechloriden eingesetzt.
[EN] N-SUBSTITUTED HYDROXAMIC ACIDS WITH CARBON-BASED LEAVING GROUPS AS EFFICIENT HNO DONORS AND USES THEREOF<br/>[FR] ACIDES HYDROXAMIQUES N-SUBSTITUÉS COMPORTANT DES GROUPES PARTANTS À BASE DE CARBONE SERVANT DE DONNEURS DE HNO EFFICACES ET UTILISATIONS DE CEUX-CI
申请人:UNIV JOHNS HOPKINS
公开号:WO2016210392A1
公开(公告)日:2016-12-29
N-substituted hydroxamic acids with carbon-based leaving groups as efficient HNO donors are disclosed. Pharmaceutical compositions and kits comprising such compounds, and methods of using such compounds or pharmaceutical compositions also are disclosed.