Expedited Baeyer–Villiger oxidation of steroidal ketones by microwave irradiation
作者:Juri Moni Borah、Pritish Chowdhury
DOI:10.1016/j.steroids.2011.06.014
日期:2011.11
compounds. Considering the remarkable application of Baeyer-Villiger (BV) reaction in the synthesis of natural products and steroid-peptide conjugates, we report here some of our findings of BV oxidation of carbonyl compounds with special reference to steroidalketones under MW irradiation justifying its accelerating effect.
Steroidal .alpha.-methylene .delta.-lactones as potential antitumor agents
作者:Shangara S. Dehal、Brian A. Marples、Reginald J. Stretton、John R. Traynor
DOI:10.1021/jm00175a019
日期:1980.1
Four novel steroidal alpha-methylene delta-lactones have been synthesized and shown to be active against human nasopharyngeal carcinoma (KB) cells in culture. The syntheses involved the use of known alpha-methylenation procedures. In addition, the lactone 6 was directly methylenated by reaction with CH2O/KOH or Et2NH/CH2O/Et2NH.HCl. The formation of a cysteine adduct (15) with the alpha-methylene lactone
已经合成了四种新颖的甾族α-亚甲基δ-内酯,它们在培养中对人鼻咽癌(KB)细胞具有活性。合成涉及使用已知的α-甲基化方法。另外,内酯6通过与CH 2 O / KOH或Et 2 NH / CH 2 O / Et 2 NH·HCl反应而直接被甲基化。据报道与α-亚甲基内酯10形成半胱氨酸加合物(15)。
Synthesis of Some Five- and Six-Membered Oxasteroids of Cholestane Series by Ring Contraction and the Mass Spectrometric Fragmentations of Oxasteroids
作者:Hiroshi Suginome、Shinji Yamada
DOI:10.1246/bcsj.60.2453
日期:1987.7
Synthesis of several new five- and six-membered oxasteroids of the cholestane series by the ring contraction of those oxasteroids whose oxygen-containing ring is larger by one member has been achieved. Ring contraction utilizes a series of reactions recently developed by us for the transformation of cyclic ketones into cyclic ethers; it involves a regioselective β-scission of the alkoxyl radical generated
Stereochemical studies. XI. Equilibria between δ-hydroxy-acids and δ-lactones in aqueous tetrahydrofuran. Relative stabilities of isomeric δ-lactones
作者:John T. Edward、Ellen Cooke、Themistocles C. Paradellis
DOI:10.1139/v82-367
日期:1982.10.15
equilibrium constants K′ for the hydrolysis of 13 δ-lactones to hydroxy-acids in 54% (mol/mol) aqueous tetrahydrofuran at 25 °C have been determined. The equilibrium constants for the isomerization of the five δ-lactones into their epimers, and for the isomerization of their hydroxy-acids into their epimers, have been calculated by the methods of conformational analysis. These calculated values are consistent
Diastereodivergent Synthesis of A-Ring Lactones Derived from Cholesterol and Diosgenin: A Convenient Solution for an Old Problem – NMR and X-ray Characterization
作者:Martín A. Iglesias-Arteaga、William H. García-Santos、Paola Valente-Valdovinos、Álvaro J. Cortina-Mendoza、Marcos Flores-Álamo
DOI:10.1055/a-2338-4149
日期:2024.10
convenient protocol for the synthesis of A-ring lactones derived from cholesterol was developed. A lactone reduction–lactol separation–reoxidation sequence, applied to the inseparable mixture of diastereomeric lactones, allows the production of multigram amounts of each lactone in pure form. The same sequence applied to A-ring lactones derived from diosgenin produced similar results. A detailed NMR
开发了一种用于合成源自胆固醇的 A 环内酯的便捷方案。内酯还原-内醇分离-再氧化顺序应用于不可分离的非对映内酯混合物,可以生产数克量的纯内酯。对源自薯蓣皂苷元的 A 环内酯应用相同的序列产生了类似的结果。还提供了所有获得的内酯的详细 NMR 表征。 X射线衍射证实了所得化合物的结构。