共查询到20条相似文献,搜索用时 15 毫秒
1.
J.S. Yadav K. Premalatha S.J. Harshavardhan B.V. Subba Reddy 《Tetrahedron letters》2008,49(48):6765-6767
The synthesis of the styryl lactone Leiocarpin C has been achieved in a highly stereoselective manner using Jacobsen’s kinetic resolution, Sharpless asymmetric epoxidation and Sharpless asymmetric dihydroxylation as key steps. This is the first total synthesis of Leiocarpin C, and thus establishes for the first time the absolute stereochemistry of this natural product. 相似文献
2.
An efficient synthesis of (+)- and (−)-deoxoprosophylline was accomplished from the readily available cis-2-butene-1,4-diol in which the Sharpless asymmetric dihydroxylation was used as the key step. 相似文献
3.
Flavan-3-ols are a series of natural products widely present in plants and show versatile biological activities. The structures of such compounds are characterized by owing two adjacent chiral centers and three rings. Their interesting structures and promising biological activities have driven increasing research developments toward the preparation of enantioenriched flavan-3-ols. This review summarizes the recent approaches for the asymmetric synthesis of chiral flavan-3-ols from two strategies in the construction of chiral centers. The key steps in the synthetic protocol involve Sharpless asymmetric dihydroxylation, Shi asymmetric epoxidation and Sharpless asymmetric epoxidation. 相似文献
4.
The asymmetric synthesis of (+)-Cladospolide C has been achieved in 11 steps with 26% overall yield. Key steps in the sequence involve KAPA-promoted alkyne Zipper reaction, TPP-promoted enyne ester (ynoate) to diene ester (dienoate) isomerization, Sharpless asymmetric dihydroxylation and Yamaguchi macrolactonization. 相似文献
5.
A highly stereocontrolled asymmetric total synthesis of epimer of (+)-7-deoxypancratistatin has been achieved from readily available starting materials via unified strategy employing Sharpless asymmetric dihydroxylation, ring closing metathesis, Overman rearrangement, hydrogenolysis and Bischler–Napieralski reaction in 15 purification steps with 15% overall yield. 相似文献
6.
Gowravaram Sabitha C. Nagendra Reddy Peddabuddi Gopal J.S. Yadav 《Tetrahedron letters》2010,51(43):5736-5739
A convergent stereoselective total synthesis of (+)-anamarine via cross-metathesis (CM) protocol starting from 2-butyn-1,4-diol and vinyl lactone is reported. Other key features of the strategy include the use of Sharpless asymmetric epoxidation, Sharpless dihydroxylation, and Red-Al reduction. 相似文献
7.
Hydroxy propiolate rearrangement to conjugated diene, Sharpless asymmetric dihydroxylation and one-pot quinolizine construction have been used as key steps in the total synthesis of (−)-epiquinamide. 相似文献
8.
R. Sateesh Chandra Kumar 《Tetrahedron letters》2010,51(7):1114-7854
An efficient stereoselective synthesis of dendrobate alkaloid (+)-241D and its C-4 epimer was achieved from the inexpensive, commercially available starting material decanal (10) in an overall yield of 21.9% and 21.1%, respectively. This synthesis utilizes the key steps of Maruoka asymmetric allylation, one-pot epoxidation followed by nucleophilic addition of an organomagnesium reagent (Forsyth’s protocol) and subsequent functional group transformations. 相似文献
9.
The first stereoselective total synthesis of seimatopolide A (1) has been achieved. The key steps are Keck allylation, Sharpless asymmetric dihydroxylation, cross-, and ring-closing metathesis reactions. 相似文献
10.
An enantioselective route for the synthesis of key fragment C1-C20 resident in microsclerodermins A and B is described. The route features deoxygenative rearrangement of an hydroxy-alkynoate and a highly enantio- and diastereo-controled iterative dihydroxylation as key reactions, starting from S-(−)-citronellol. 相似文献
11.
Takashi Nishiyama Shuuya Takaiwa Rika Kotouge Satomi Tani Rikako Yoshinaga Erina Hamada Mai Endo Yuka Sugino Noriyuki Hatae Satoshi Hibino Tominari Choshi 《Tetrahedron letters》2019,60(48):151278
In this study, the first asymmetric enantioselective total syntheses of (+)-asiaticumine A (2) and its enantiomer were accomplished through a seven-step sequence using the bond formation between the C4a and N5 positions of the phenanthridine framework based on the microwave-assisted electrocyclization of cyclohexenylbenzaldoxime methyl ether as an aza 6π-hexatriene system followed by the Sharpless asymmetric dihydroxylation as the key step. In addition, the absolute configuration of natural (+)-2 was determined to be S by Mosher’s method. 相似文献
12.
Sudina Purushotham Reddy Baggu Chinnababu Yenamandra Venkateswarlu 《Helvetica chimica acta》2014,97(7):999-1003
The first concise stereoselective total synthesis of diarylheptanoid rhoiptelol C ( 1 ) was achieved from readily available vanillin. The synthesis involves Keck's asymmetric allylation, olefin cross metathesis, and Sharpless asymmetric dihydroxylation reaction as key steps. 相似文献
13.
Cryptomoscatone D2 was synthesized stereoselectively from trans-cinnamaldehyde. The synthesis of the triol frame work relied on the creations of the stereocenters independently by utilizing double Maruoka allylations and Sharpless epoxidation. The lactone moiety was constructed by RCM reaction. 相似文献
14.
A stereoselective synthesis of functionalized tetrahydropyran D‐ring of methyl sartortuoate ( 1 ) was achieved starting from geraniol in a high yield. Sharpless asymmetric kinetic resolution, asymmetric dihydroxylation as well as asymmetric epoxidation were applied as key steps to establish all the four stereocenters of the D‐ring. 相似文献
15.
Zhi-Xiang FengWei-Shan Zhou 《Tetrahedron letters》2003,44(3):497-498
A total synthesis of (+)-lentiginosine was achieved by using ethyl 3-(pyridin-2-yl)acrylate N-oxide as the starting material and an improved Sharpless asymmetric dihydroxylation as the key step. 相似文献
16.
G. ShankaraiahR. Sateesh Chandra Kumar B. PoornimaK. Suresh Babu 《Tetrahedron letters》2011,52(38):4885-4887
A simple and efficient stereoselective synthesis of naturally occurring pyrrolidine alkaloid, radicamine B has been accomplished in 13 steps from the commercially available starting materials with an overall yield of 9.75%. The synthesis utilizes Sharpless asymmetric epoxidation and Horner-Wadsworth-Emmons (HWE) olefination as key steps. 相似文献
17.
Olefin cross-metathesis approach to (+)-cardiobutanolide has been achieved starting from d-mannitol utilizing Sharpless kinetic resolution and Sharpless asymmetric dihydroxylation. 相似文献
18.
Microcarpalide is a strong microfilament disrupting agent. The convergent and stereoselective synthesis of microcarpalide was succeeded via Julia olefination and macrolactonization. 相似文献
19.
Xiaoyu Li Xiaozhen JiaoXiaoyu Liu Chengsen TianLiang Dong Yangyang YaoPing Xie 《Tetrahedron letters》2014
A practical total synthesis of the natural products (+)-isogalbulin and (+)-galbulin has been achieved in 10 steps from readily available 3-(3,4-dimethoxyphenyl)propanoic acid. The total yields were 12.3% and 12.9%, respectively. The key steps involved Evans asymmetric alkylation, Sharpless asymmetric epoxidation, and a highly regioselective opening of 1-benzyloxy-2,3-epoxides with an organoaluminum ate-complex formed by Me3Al and n-BuLi. 相似文献
20.
Ashish Garg 《Tetrahedron》2006,62(48):11240-11244
A formal total synthesis of (+)-cardiobutanolide has been accomplished from d-glucose, a readily available precursor. 相似文献