Synthesis of (1S,4R)-4-isopropyl-1-methyl-2-cyclohexen-1-ol,the aggregation pheromone of the ambrosia beetle Platypus quercivorus,its racemate, (1R,4R)- and (1S,4S)-isomers

(S)-Perillyl alcohol was converted to (R)-cryptone (91.5–93% ee) in six steps, which was then treated with methyllithium to give (1S,4R)-4-isopropyl-1-methyl-2-cyclohexen-1-ol, the aggregation pheromone of the ambrosia beetle Platypus quercivorus. The racemic pheromone was also prepared by methylation of (±)-cryptone. Both (1R,4R)- and (1S,4S)-isomers (98% ee) of the pheromone were synthesized from the enantiomers of dihydrolimonene oxide.     

Computational study of the energetics of 3Fe(CO)4, 1Fe(CO)4 and 1Fe(CO)4(L), L = Xe, CH4, H2 and CO

Large basis CCSD(T) calculations are used to calculate the energetics of 3Fe(CO)4, 1Fe(CO)4 and 1Fe(CO)4(L), L = Xe, CH4, H2 and CO. . The relative energy of the excited singlet state of Fe(CO)4 with respect to the ground triplet state is not known experimentally, and various lower levels of theory predict very different results. Upon extrapolating to the infinite basis set limit, and including corrections for core-core and core-valence correlation, scalar relativity, and multi-reference character of the wavefunction, the best CCSD(T) estimate for the spin-state splitting in iron tetracarbonyl is 2 kcal mol(-1). Calculation of the dissociation energy of 1Fe(CO)4(L) into singlet fragments, taken together with known experimental behaviour of triplet Fe(CO)4, provides independent evidence for the fact that the spin-state splitting is smaller than 3 kcal mol(-1). These calculations highlight some of the challenges involved in benchmark calculations on transition metal containing systems.     

Conformational Analysis of Germacrane Sesquiterpene Lactones. 1(10)Z,4E- and 1(10)E,4Z-Germacranolides

Molecular mechanics was used to study the structures of 1(10)Z,4E- and 1(10)E,4Z-germacranolides. Possible conformers, their probabilities, and barriers to conformational transitions were determined     

Asymmetric syntheses of (1r,3R,4S)- and (1s,3R,4S)-(3,4-difluorocyclopentyl)-alanine derivatives

By employing a sequence of epoxide opening, asymmetric alkylation, and fluorination, polyfluorinated cyclopentylamino acids with defined stereochemistries were prepared.     

双(4,5-二氮杂芴酮)缩对,对''-二氨基二苯甲烷桥联的二(邻菲咯啉合铜(Ⅱ))的合成及其与DNA作用的光谱研究

研究金属配合物与核酸的作用方式和识别机理对深入了解核酸结构，功能及某些抗肿瘤药物机理有着重要意义。自１９８２年Barton犤１犦报道了第一个具有立体选择性的DNA插入剂Zn（phen）３２＋（phen为邻菲咯啉）之后，金属多吡啶配合物与DNA的相互作用成为国际上较活跃的研究领域之一。以邻菲咯啉为代表的多吡啶配体的四面体铜，八面体钌、铑、钴等配合物已广泛地被用于该领域的研究。近年来，多吡啶配体的过渡金属多核配合物与核酸的作用的研究也逐渐增多犤２犦。自从Sigman等人首先发现四面体配合物Cu（phen）２＋能够在O２和还原剂存…     

Synthesis and study of poly (1, 3, 4-oxadiazoles)

Various conditions for synthesizing poly (1,3,4-oxadiazoles) from carboxylic acids, their hydrazides, and polyhydrazides, are investigated. Methods of cyclodehydration of polyhydrazides using phosphorus oxychloride, sulfuric acid, and certain other reagents are not of general utility for synthesizing poly (1,3,4-oxadiazoles). Vacuum-heating polyhydrazides gives crosslinked polymers. A new method of preparing poly (1,3,4-oxadiazoles) is offered. It is the reaction of hydrazine sulfate or dihydrazides of acids with dicarboxylic acids in oleum solution. Some chemical properties of the compounds synthesized are investigated.     

Synthesis and Bioactivity of Novel Aminomethyl-2-（1, 2,4-triazol）-4, 4-dimethyl-3-pentanone （ol）

3, 3-Dimethyl-1-(1,2,4-triazol)-2-butanone was treated with aqueous formaldehyde to give an additional product, and subsequent elimination by acetic anhydride yielded 4,4-dimethyl-2-(1,2,4-triazol)-1-penten-3-one. Further addition with substituted amines provideda series of (1,2,4-triazol)-4,4-dimethyl-3-pentanone, which were then reduced by KBH4 to obtaina series of (1,2,4-triazol)-4,4-dimethyl-3-pentanol. Their structures were confirmed by ^1HNMR and elemental analysis. The results of bioassay showed that the title products possess good fungicidal activities.     

Synthesis, Crystal Structure and Fluorescent Properties of 1-（4-（Dimethylamino）benzylidene）- 4-（naphthalen- 1-yl） Thiosemicarbazide

1 INTRODUCTION Recently, for the fluorescent properties, Schiff base has been more and more important and widely studied in density optical memories, nonlinear op- tics (NLO), organic light-emitting diodes (OLED), polymer LED and electrogenerated chemilumines- cence (ECL)[1~5]. Thiosemicarbazones are a kind of Schiff bases with thiourea and good ligands easily chelating with transition metal ions. Although they have been studied extensively for a long time due to their chemical and b…     

Biopreparation of (-)-(1S,3R,4S,6S)-6-hydroxymenthol and (-)-(1S,3R,4S)-1-hydroxymenthol from 1-menthol by Rhizoctonia solani AG-1-IA and IB

Microbial transformation of 1-menthol (1) by six isolates of soil-borne plant pathogenic fungi Rhizoctonia solani AG-1-IA (Rs24, Joichi-2 and RRG97-1) and AG-1-IB (TR22, R147 and 110.4) as a biocatalyst was investigated. Twenty one days precultivation of Rhizoctonia solani AG-1-IA Rs24 and AG-1-IB 110.4 showed excellent yield (98.5-98.6%) of (-)-(1S,3R,4S,6S)-6-hydroxymenthol (2) and (-)-(1S,3R,4S)-1-hydroxymenthol (3) from 1.     

Synthesis of 4-(1-Adamantyl)- and 4-(1-Adamantylmethyl)-substituted Halothiazoles

1-Adamantyl bromomethyl ketone and 1-adamantylmethyl chloromethyl ketone react with potassium thiocyanate in dimethylformamide to give the corresponding thiocyanatoketones which cyclize under the influence of HCl into 4-(1-adamantyl) and 4(-adamantylmethyl)chlorothiazole respectively. 4-(1-Adamantyl)-2-amino-5-bromothiazole and its N-derivative were synthesized by the reaction of 1-adamantyl dibromomethyl ketone with thioureas and N-substituted thiourea in acetonitrile.