88980-13-6Relevant academic research and scientific papers
Diastereoselective oxygen to carbon rearrangements of anomerically linked enol ethers and the total synthesis of (+)-(S,S)-(cis-6-methyltetrahydropyran-2-yl)acetic acid, a component of civet
Dixon, Darren J.,Ley, Steven V.,Tate, Edward W.
, p. 2385 - 2394 (2000)
A range of enol ethers, linked via their oxygen atom to the anomeric centre of a pyran ring system, was shown to undergo oxygen to carbon rearrangement upon treatment with a Lewis acid to give the corresponding 2-carbon substituted products. At low temperature, trimethylsilyl trifluoromethanesulfonate catalysed rearrangements of anomerically linked 6-substituted tetrahydropyranyl enol ethers gave selectively the trans-pyranyl ketones, whereas at higher temperatures selective formation of the cis-pyranyl ketones was observed. In a simple application of the methodology the cis-selective rearrangement was used as the key step in a concise total synthesis of a constituent of civet.
Stereoselective total synthesis of diplodialide A
Ramakrishna, Kolluri,Sreenivasulu, Reddymasu,Rao, Mandava Venkata Basaveswara,Vidavalur, Siddaiah,Reddy, Boggu Jagan Mohan
, p. 931 - 937 (2020/10/02)
Abstract: An efficient stereoselective total synthesis of Diplodialide A has been achieved from inexpensive and commercially available starting material (R)-propylene oxide. This linear synthesis utilizes Wittig reaction, alkylation of 1,3-dithiane and Yamaguchi macrolactonization as key steps. Graphic abstract: [Figure not available: see fulltext.]
A Unified Synthetic Approach to Optically Pure Curvularin-Type Metabolites
Allu, Srinivasa Rao,Banne, Sreenivas,Jiang, Jia,Qi, Na,Guo, Jian,He, Yun
, p. 7227 - 7237 (2019/06/07)
A unified and concise approach to the synthesis of nine curvularin-type metabolites and two analogues has been developed with few steps and high yields. Among them, sumalactones A-D were synthesized for the first time. The key steps in this approach inclu
CREATINE PRODRUGS, COMPOSITIONS AND METHODS OF USE THEREOF
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Paragraph 00703; 00704, (2019/06/17)
The present disclosure provides creatine prodrug analogs and their compositions useful for the treatment of creatine deficiencies.
Total synthesis and stereochemical revision of relgro and 10′-oxorelgro
Gaddam, Janardhan,Reddy, G. Sudhakar,Marumudi, Kanakaraju,Kunwar, Ajit C.,Yadav, Jhillu S.,Mohapatra, Debendra K.
, p. 5601 - 5614 (2019/06/13)
The first asymmetric total synthesis and stereochemical assignments of 10-membered macrolactones relgro and 10′-oxorelgro are disclosed. To this end, palladium-catalyzed Stille coupling, the Mitsunobu reaction, ring-closing metathesis, EDCI promoted coupling and the Jacobsen hydrolytic kinetic resolution are used as key steps. The total synthesis followed by thorough evaluation of the optical rotation and CD spectral data led to the revision of the absolute configuration at C-6′ for both relgro and 10′-oxorelgro. Moreover, the 1H as well as 13C NMR data are reported for the first time for relgro.
An alternative total synthesis of diplodialide-B
Kalavakuntla, Chiranjeevi,Kummari, Vijaya Babu,Yadav, Jhillu Singh
, p. 3324 - 3328 (2019/11/11)
In this paper, an enantioselective synthesis of diplodialide-B has been described. To accomplish this target, a combination of regioselective ring opening of the chiral epoxide, Jacobsen hydrolytic kinetic resolution and Yamaguchi macrolactonization were used as the key steps.
First Total Synthesis of the Proposed Structure of Pandangolide 1
Show, Krishanu,Gonnade, Rajesh G.,Kumar, Pradeep
, p. 3352 - 3364 (2018/07/13)
The first total synthesis of the proposed structure of pandangolide 1 is reported. The synthesis was carried out using both an organocatalytic approach and a chiral-pool approach. The required stereochemistry at C-3 and C-5 was installed by using an organocatalytic aldol reaction and a stereoselective ketone reduction. The construction of the 12-membered core was achieved by 2-methyl-6-nitrobenzoic anhydride-mediated Shiina lactonization. The structure of target molecule was confirmed unambiguously by single-crystal X-ray analysis, but the optical rotation and NMR spectroscopic data of the synthetic pandangolide 1 were found to be inconsistent with the natural product.
A facile, efficient and chemoseletive deprotection of silyl ethers using zinc (II) trifluoromethanesulfonate
Reddy, Kotthireddy Thirumal,Sreenivasulu, Reddymasu,Veronica, Deekala,Chandrasekhar, Choragudi,Anitha, Kowthalam,Raju, Rudraraju Ramesh
, p. 191 - 195 (2018/03/09)
Background: A number of protective groups for hydroxyl functional groups have been developed to date. Alcohols are most commonly protected as ethers and esters, where in alkyl and benzyl ethers are strong protective groups while others, like THP, TBS, TPS and MEM/MOM ethers are acid labile. Among all other hydroxyl protecting groups, Silyl ethers are the most frequently used protecting groups because they are easily and efficiently installed and are stable to a variety of useful reagents and reaction conditions. Among the silyl ethers, triethylsilyl (TES), tert-butyldimethylsilyl (TBDMS), triisopropylsilyl (TIPS), and tert-butyldiphenylsilyl (TBDPS) moieties are the frequently used hydroxyl protecting groups in multi step organic syntheses. Methods: A mild, efficient and selective method for the deprotection of variety of silyl ethers developed in high yields by using 20 mol % of Zinc (II) trifluoromethanesulfonate (Zn(OTf)2) at room temperature in methanol as a solvent without affecting both the acid and base sensitive protecting groups was reported. Results: To study the generality of this methodology, several silyl ethers were prepared from a variety of substrates having different protecting groups and subjected to desilylation using Zn(OTf)2 in MeOH. Conclusion: In conclusion, mild and efficient protocols for the deprotection of variety of silyl ethers using 20 mol % of Zn(OTf)2 at room temperature in MeOH have been established, in which both the acid and base sensitive groups are unaffected.
Determination of the Absolute Configuration of Gliomasolide D through Total Syntheses of the C-17 Epimers
Seetharamsingh,Ganesh, Routholla,Reddy, D. Srinivasa
, p. 560 - 564 (2017/03/09)
The absolute configuration at C-17, the carbon bearing the distal hydroxy group of the 14-membered natural product gliomasolide D, was assigned as R by comparison of 13C NMR shifts and specific rotation values of the epimers at C-17. The first
Enantioselective synthesis of (2R,13R,8Z)-2,13-diacetoxy-8-heptadecene, the major component of the sex pheromone of the pear leaf midge, Dasineura pyri
Zhou, Yun,Yang, Pengfei,Li, Shuoning,Wang, Lifeng,Yin, Jingwei,Zhong, Jiangchun,Dong, Yanhong,Liu, Shangzhong,Wang, Min,Bian, Qinghua
, p. 338 - 343 (2017/02/18)
The first enantioselective synthesis of (2R,13R,8Z)-2,13-diacetoxy-8-heptadecene 1, the major component of the sex pheromone of the pear leaf midge, Dasineura pyri, has been achieved. The key steps include the (R,R)-BINOL/Ti(OiPr)4catalyzed alkynylzinc addition to an unsaturated aldehyde, the ring-opening of the chiral epoxide with a Grignard reagent, and the partial reduction of an acetylenic diol ester to a (Z)-olefinic diol ester with hydrogen and P2-Ni.
