Structures and stability of N9, N9 − and N9 + clusters

 Ab initio molecular orbital calculations for N₉, N⁻ ₉ and N⁺ ₉ isomers were carried out at the HF/ 6-31G*, B3PW91/6-31G*, B3LYP/6-31G* and MP2/ 6-31G* levels of theory. Stable equilibrium geometric structures were determined by harmonic vibrational frequency analyses at the HF/6-31G*, B3PW91/6-31G* and B3LYP/6-31G* levels of theory. The most stable free-radical N₉ cluster is structure 1 with C _{2 v} symmetry and that of anion N⁻ ₉ is structure 3 with C _s symmetry. Only one stable structure of the N⁺ ₉ cation with C _{2 v} symmetry was predicted. Their potential application as high-energy-density materials has been examined. Received: 15 June 1999 / Accepted: 11 October 1999 / Published online: 14 March 2000     

蜜蜂外激素9－ODA和9－HDA的合成

６－溴－２－己酮在Ｌｉ２ｃｕＣｌ４催化下与γ－溴代巴豆酸甲酯进行格氏偶联，合成了蜂王物质９－羰基－（Ｅ）－２－癸烯酸（９－ＯＤＡ），将其还原得到另一蜂王物质９－羟基－（Ｅ）－２－癸烯酸（９－ＨＤＡ）。该法是合成９－ＯＤＡ和９－ＨＤＡ的新路线。     

蜜蜂外激素9—ODA和9—HDA的合成

６－溴－２－己酮在Ｌｉ２ＣｕＣｌ４催化下与γ－溴代巴豆酸甲酯进行格氏偶联，合成王物质９－羰基－（Ｅ）－２癸烯酸（９－ＯＤＡ），将其还原得到了另一蜂王物质９－羟基－（Ｅ）－２－癸烯酸（９－ＨＤＡ）。该法是合成９－ＯＤＡ和９－ＨＤＡ的新路线。     

High-pressure access to the Δ9-cis- and Δ9-trans-tetrahydrocannabinols family

Diels-Alder reactions of a range of 1-(alkoxy/alkyl-substituted phenyl)buta-1,3-dienes with methyl vinyl ketone and methyl acrylate carried out in ethanol as the reaction medium under 9 kbar pressure were investigated. The use of high pressure as the activating method of the Diels-Alder reactions allows the efficient and endodiastereoselective generation of a series of cis-cyclohexenyl-benzene cycloadducts, which are selectively converted into their trans-epimers. The cis-cyclohexenyl-benzenes and trans-cyclohexenyl-benzenes produced are useful precursors for accessing substituted privileged cis-6a,7,8,10a-tetrahydro-6H-benzo[c]chromene and trans-6a,7,8,10a-tetrahydro-6H-benzo[c]chromene skeletons. The total syntheses of Δ(9)-cis-tetrahydrocannabinol (THC) and Δ(9)-trans-THC, through the use of selected Diels-Alder adducts, are described. Finally, a route for obtaining Δ(9)-trans-THC in both enantiomeric pure forms based on the (S)-(-)-1-amino-2-(methoxymethyl)pyrrolidine (SAMP)-hydrazone method is also reported.     

9-羟基-芴-9-羧酸甲酯的晶体结构

9-羟基-芴-9-羧酸衍生物是一种植物生长调节剂。它能引起植物形态变化,还能增强苯氧烷基羧酸类防落素的作用,已广泛应用于名贵花卉和果树等。然而,芴和9-羟基-芴-9-羧酸衍生物的晶体结构均未见报道。本文报告了9-羟基-芴-9-羧酸甲酯的晶体结构。     

Hypervalent-Iodine-Mediated Carbon–Carbon Bond Cleavage and Dearomatization of 9H-Fluoren-9-ols

A transition-metal-free synthesis of spiro compounds from 9H-fluoren-9-ols mediated by hypervalent iodine is reported. In this reaction, an unprecedented β-carbon elimination of tertiary alkoxyliodine(III) to form new diaryliodonium salts is proposed. The obtained phenol intermediates undergo oxidative dearomatization to furnish a class of oxo-spiro compounds. This domino reaction significantly increases the complexity of these molecules and shows excellent regio- and stereoselectivity.     

SYNTHETIC STUDIES ON 9-HYDROXY-CEMBRENE-C

A dicarbonyl precursor of 9-hydroxy-cembrene-C,8-tetrahydropyranoxy-3,7,11,15-tetramethyl-14-oxo-2E,6E,10E-hexdecatrienal,was prepared from farnesyl acetate via four steps.     

Synthesis of 9-oxiranyl-9H-purine derivatives in β-cyclodextrin cavity

An efficient and mild method has been developed for the preparation of 9-oxiranyl-9H-purine derivatives. This reaction proceeds smoothly in β-cyclodextrin cavity at room temperature, giving good to excellent yields.     

辅酶Q9的合成

以辅酶Q0为起始原料,经Diels-Aider加成,缩合和逆Dicls-Alder分解反应,合成了辅酶Q10的类似物辅酶Q9,总收率61.9%.中间体和Q9的结构经1H NMR和EI-MS表征.     

Fu-9及含硼Fu-9型分子筛的合成及其酸性研究

合成了SiO_2-Al_2O_3-NaOH-TMA-H_2O体系的Fu-9型分子筛和SiO_2-Al_2O_3-H_3BO_3-NaOH-TMA-H_2O体系的Bi-Si-Al的Fu-9型分子筛,并且得到了后者的三元晶化区域图。用X射线衍射图和固态高分辨~(11)B核磁共振谱研究了这些分子筛的结构,表明硼原子处在沸石正四面体位置上。用程序升温脱附方法研究了它们的表面酸性质。     

An easy route to exotic 9-epimers of 9-amino-(9-deoxy) cinchona alkaloids with(8S,9R) and(8R,9S)-configurations through two inversions of configuration

Four exotic chiral organocatalysts, 9-amino-（9-deoxy） cinchona alkaloids with （8S, 9R） and （8R, 9S）- configurations, were conveniently synthesized for the first time in 27-72% total yields through two conversions of configuration at the 9-stereogenic centers of commercially available cinchona alkaloids.     

Editorial board page for “Analytical Letters”, Volume 9, Number 9

Abstract

This is a scanned image of the original Editorial Board page(s) for this issue.