نتایج جستجو برای: chiral spiro oxindolopyrrolidines

تعداد نتایج: 39527  

In the present paper, the expressions for scalar and vector potentials in lossless isotropic chiral media are analyzed. Propagating eigenvalues of these potentials are then obtained. Furthermore by decomposition of sources and fields in a chiral medium, we introduce the auxiliary right-and left-handed potentials and find the associated fields. These potentials are used to solve the problem of a...

Journal: :Chemical communications 2013
Qiao Chen Jinyan Liang Shoulei Wang Dong Wang Rui Wang

The first organocatalytic Michael-cyclization cascade reaction between isothiocyanato oxindoles and unsaturated pyrazolones has been developed. The multicyclic spiro[oxindole/thiobutyrolactam/pyrazolone] core structures containing three contiguous stereogenic centers, including two spiro quaternary centers, were prepared with excellent diastereo- (up to >20 : 1) and enantioselectivities (up to ...

Journal: :Organic & biomolecular chemistry 2013
Sandeep Rana Amarnath Natarajan

We report an unusual face selective reduction of the exocyclic double bond in the α-methylene-γ-butyrolactone motif of spiro-oxindole systems. The spiro-oxindoles were assembled by an indium metal mediated Barbier-type reaction followed by an acid catalyzed lactonization.

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1377

در این پایان نامه با هدف نهایی تعیین بار فرمیونی سالیتونها، جفت شدگی میدانهای فرمیونی و سالیتونی در نظر گرفته شده است . در فصل اول مفاهیم سالیتون و امواج سالیتاری مورد بررسی قرار گرفته، و در این راستا چنین امواجی با مثالهایی در 1+1 و 1+2 بعد توصیف گردیده اند. در فصل دوم قطبیده شدن خلاء فرمیون (vacuum polarization: vp) در حضور میدان سالیتونی مورد بررسی قرار گرفته. در این زمینه در سال 1994 گوشه و...

Journal: :Journal of the Institute of Brewing 1970

A common approach in resolving enantiomers of chiral basic drugs by capillary electrophoresis (CE) is to use cyclodextrins (especially their anionic derivatives) as chiral selector in the acidic buffer (pH ≤ 3) in normal or reversed (carrier) mode. Then, some organic modifiers are added to the buffer solution if the resolution is not satisfactory. In case of cetirizine (CTN), applying the same ...

2014
E. M. Kithsiri Wijeratne Patricia Espinosa-Artiles Raphael Gruener A. A. Leslie Gunatilaka

Four new nor-spiro-azaphilones, thielavialides A-D (1- 4), a new bis-spiro-azaphilone, thielavialide E (5), together with pestafolide A (6), were isolated from the endophytic fungal strain, Thielavia sp. PA0001, occurring in the healthy leaf tissue of aeroponically grown Physalis alkekengi. The structures and relative configurations of 1-5 were established on the basis of their MS and NMR data....

2009
Tie-Ying Zi Zhi-He Zang Ming-Yong Yuan Ling-Li Zheng

The title compound, C(27)H(40)O(4), was obtained from the oxidation of (25R)-3b-hydr-oxy-5a-spiro-stan-12-one (Hecogenin) by Jone's reagent. The mol-ecule contains six alicyclic and heterocyclic rings, all trans-fused, among which four six-membered rings adopt similar chair conformations while two five-membered rings assume an envelope conformation.

2015
Sambasivarao Kotha Ajay Kumar Chinnam Rashid Ali

We have developed a simple methodology to transform cis-syn-cis-triquinane derivative 2 into the diindole based macrocycle 6 involving Fischer indolization and ring-closing metathesis (RCM). Various spiro-polyquinane derivatives have been assembled via RCM as a key step.

Journal: :international journal of nanoscience and nanotechnology 2013
n. farhadian

the aim of this study is investigating the transport mechanism of ibuprofen chiral isomers inside singlewall carbon nano tube (swcnt) using mathematical modeling. to achieve this goal, molecular dynamicssimulation has been performed to evaluate the interactions of ibuprofen isomers with swcnt in an aqueoussolution. results show that both chiral forms of ibuprofen molecules enter and remain insi...

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