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文章名     作者     期刊名     摘要     卷     期         如果没有找到您所需要的文献，请点击 ——此处申请     共18条记录   Enantiomerically pure poly(oxymethylene) helices: Correlating helicity with centrochirality [作者：Eppacher, S; Giester, G; Bats, JW; Noe, CR,期刊：Helvetica Chimica Acta, 页码：581-597 , 文章类型： Article，,卷期：2008年91-4] A first series of enantiomerically pure helical oligo (formaldehyde)s (=oligo(oxymethylen)s) 16-20 was synthesized. To induce the chiral uniformity of the helices, we used (IS)-2,2-dimethyl-l-phenylpropan-1-ol (14) to ge... Synthesis of (+)-13-stemarene and (+)-18-deoxystemarin: Expeditious preparation of the key 6-exo-Hydroxybicyclo[2.2.2]octan-2-one ethylene dithioacetal [作者：Leonelli, F; Caschera, B; Silvestri, L; Prastaro, A; Corso, G; Ceccacci, F; La Bella, A; Migneco, LM; Bettolo, RM,期刊：Helvetica Chimica Acta, 页码：598-607 , 文章类型： Article，,卷期：2008年91-4] An expeditious preparation of the 6-exo-hydroxybicyclo[2.2.2]octan-2-one ethylene dithioacetal 2b, a key intermediate in the synthesis of (+)-13-stemarene (4) and (+)-18-deoxystemarin (5) is described. Compound 2b was ob... Novel aspects of a convenient synthesis and of electroproperties of derivatives based on diphenylamine [作者：Idzik, K; Soloducho, J; Cabaj, J; Mosiadz, M; Lapkowski, M; Golba, S,期刊：Helvetica Chimica Acta, 页码：618-627 , 文章类型： Article，,卷期：2008年91-4] The substituted monomers 4a,c,d, 5a,b, 6a, 7a,b, and 8a of novel poly(diphenylamines), possessing the respective photochromic groups, were synthesized by the Stille cross-coupling methodology (Scheme). The hyperbranched ... Four new neoclerodane diterpenoids from Ajuga decumbens [作者：Huang, XC; Qin, S; Guo, YW; Krohn, K,期刊：Helvetica Chimica Acta, 页码：628-634 , 文章类型： Article，,卷期：2008年91-4] Four new neoclerodane diterpenoids, 15-epilupulin A (1), 6-O-deacetylajugamarin (2), and ajugadecumbenins A (3) and B (4), were isolated from the whole plants of Ajuga decumbens. Their structures were elucidated on the b... Colorimetric fluoride-anion sensor based on intramolecular hydrogen bonding and enol-keto tautomerization of a phenothiazine derivative [作者：Han, F; Zhao, JZ,期刊：Helvetica Chimica Acta, 页码：635-645 , 文章类型： Article，,卷期：2008年91-4] A colorimetric sensor for fluoride ions based on a new sensing mechanism is reported. The colorimetric sensor contains an isomerizable enol-keto moiety as the recognition site and phenothiazine as chromogenic center. A c... Iridoid glycosides from Gardenia jasminoides ELLIS [作者：Fu, XM; Chou, GX; Wang, ZT,期刊：Helvetica Chimica Acta, 页码：646-653 , 文章类型： Article，,卷期：2008年91-4] Three new iridoid glycosides, 4 ''-O-[(E)-p-coumaroyl]gentiobiosylgenipin (1), 6'-O-[(E)-caffeoyl]deacetylasperulosidic acid methyl ester (2), and 6'-O-[(E)-sinapoyl]gardoside (3), together with seven analogues, 4-10, we... Ring opening of 2-(benzylamino)-2H-1,4-benzoxazin-3(4H)-ones and 2-bromo-2H-1,4-benzoxazin-3(4H)-ones [作者：Ilas, J; Kikelj, D,期刊：Helvetica Chimica Acta, 页码：654-664 , 文章类型： Article，,卷期：2008年91-4] Substituted 2-(benzylamino)-2H-1,4-benzoxazin-3(4H)-ones are unstable under alkaline and acidic conditions, undergoing opening of the benzoxazinone ring. 2-Bromo-2H-1,4-benzoxazin-3(4H)-ones show similar degradation unde... Triterpenoids from the edible leaves of Photinia serrulata [作者：Song, YL; Wang, YH; Lu, Q; Qiao, HJ; Cheng, YX,期刊：Helvetica Chimica Acta, 页码：665-672 , 文章类型： Article，,卷期：2008年91-4] Five new triterpenoids, serrulatins A-E (1-5), including two new artifacts, together with ten known serrulatins, were isolated from the edible leaves of Photinia serrulata after extraction and purification. Their structu... Oligonucleotide analogues with integrated bases and backbone [作者：Ritter, A; Egli, D; Bernet, B; Vasella, A,期刊：Helvetica Chimica Acta, 页码：673-714 , 文章类型： Article，,卷期：2008年91-4] The formation of cyclic duplexes (pairing) of known oxymethylene-linked self-complementary U*[o]A(()*()) dinucleosides contrasts with the absence of pairing of the ethylene-linked U*[c,]A(()*()) analogues. The origin of ... Nanocrystalline ZnO for Knoevenagel condensation and reduction of the carbon,carbon double bond in conjugated alkenes [作者：Hosseini-Sarvari, M; Sharghi, H; Etemad, S,期刊：Helvetica Chimica Acta, 页码：715-724 , 文章类型： Article，,卷期：2008年91-4] A novel efficient and eco-friendly nanocrystalline ZnO catalyst was used for the Knoevenagel condensation and for the reduction of C=C double bonds at room temperature in the absence of solvents. New sesquiterpenes from Chloranthus japonicus [作者：Wu, B; Qu, HB; Cheng, YY,期刊：Helvetica Chimica Acta, 页码：725-733 , 文章类型： Article，,卷期：2008年91-4] Chemical investigation of the roots of Chloranthus japonicus SIEB. has resulted in the isolation and characterization of four new eudesmane-type sesquiterpenes including two new sesquiterpene cinnamates, along with one n... Preparation of two diastereoisomeric decalin synthons and (-)-ambrox [作者：Xie, YP; Li, BG; Luo, YG; Chen, XZ; Zhang, GL,期刊：Helvetica Chimica Acta, 页码：734-740 , 文章类型： Article，,卷期：2008年91-4] Two diastereoisomeric decalins, (2S,4aS,5S,6R)- and (2S,4aS,5R,6R)-5-(2-hydroxyethyl)-1,1,4a,6-tetramethyldecalin-2,6-diol (5 and 6) were prepared from the degradation products of oleanolic acid. Starting from 6, (-)-amb... Novel polyketides isolated from Streptomyces sp. [作者：Li, J; Lu, CH; Shen, YM,期刊：Helvetica Chimica Acta, 页码：741-745 , 文章类型： Article，,卷期：2008年91-4] From the endophytic strain Streptomyces sp. CS of Maytenus hookeri, five novel type III polyketides, compounds 1-5, were isolated. Their structures were elucidated by spectroscopic analyses including 1D- and 2D-NMR exper... Improved synthesis of phytosphingosine and dihydrosphingosine from 3,4,6-tri-O-benzyl-D-galactal [作者：Niu, YH; Cao, XP; Ye, XS,期刊：Helvetica Chimica Acta, 页码：746-752 , 文章类型： Article，,卷期：2008年91-4] An efficient and facile synthesis of phytosphingosine and dihydrosphingosine derivatives is described with less steps and in improved overall yield (66-72%) starting from commercially available tri-O-benzyl-D-galactal. T... Modified cyclodextrins as enantioselective hosts for amino acids [作者：Kumar, VP; Suryanarayana, T; Nageswar, YVD; Rao, KR,期刊：Helvetica Chimica Acta, 页码：753-758 , 文章类型： Article，,卷期：2008年91-4] Two modified beta-cyclodextrins, H-2 and H-3, having a flexible appended moiety were studied for the chiral discrimination of the enantiomers of various amino acids by means of fluorescence as signaling option. These hos... A new diterpenoid and a new diterpenoid alkaloid from Aconitum coreanum [作者：Yang, CH; Wang, XC; Tang, QF; Liu, WY; Liu, JH,期刊：Helvetica Chimica Acta, 页码：759-765 , 文章类型： Article，,卷期：2008年91-4] A new diterpenoid, guan fu diterpenoid A (1), and a new diterpenoid alkaloid, guan fu base S (2), were isolated from the Chinese medicinal herb Aconitum coreanum (LEVL.) RAPAICS, together with five known diterpenoid alka...