136022-55-4Relevant academic research and scientific papers
Total synthesis of mycothiazole, a polyketide heterocycle from marine sponges
Sugiyama, Hideyuki,Yokokawa, Fumiaki,Shioiri, Takayuki
, p. 6579 - 6593 (2003)
Mycothiazole isolated from marine sponges has been efficiently synthesized in a convergent manner. The key reactions involve the thiazole synthesis by dehydrogenation of the thiazolidine with chemical manganese dioxide (CMD), the Stille coupling, and the Nagao asymmetric acetate aldol reaction using the chiral 1,3-thiazolidine-2-thione. This synthesis clearly established the absolute configuration of natural mycothiazole to be (R).
Diverse synthesis of the C ring fragment of bryostatins via Zn/Cu-promoted conjugate addition of α-hydroxy iodide with enone
Chu, Zhiwen,Tong, Ruiqi,Yang, Yufan,Song, Xuanyi,Hu, Tian bao,Fan, Yu,Zhao, Chen,Gao, Lu,Song, Zhenlei
, p. 1 - 4 (2020/12/21)
A convergent approach to 1,5-hydroxy ketones, the general precursors for constructing the C ring of bryostatins, has been developed via a Zn/Cu-promoted conjugate addition of α-hydroxy iodides with enones. The reaction leads to direct formation of the C21-C22 bond and tolerates diverse functionalities at the C17-, C18- and C24-positions. The approach also enables a more concise synthesis of the known C ring intermediate (10 longest linear steps and 14 total steps), in contrast to its previous synthesis (17 longest linear steps and 22 total steps) in our total synthesis of bryostatin 8.
Primary Anion–π Catalysis of Epoxide-Opening Ether Cyclization into Rings of Different Sizes: Access to New Reactivity
Matile, Stefan,Paraja, Miguel
, p. 6273 - 6277 (2020/02/28)
The concept of anion–π catalysis focuses on the stabilization of anionic transition states on aromatic π surfaces. Recently, we demonstrated the occurrence of epoxide-opening ether cyclizations on aromatic π surfaces. Although the reaction proceeded through unconventional mechanisms, the obtained products are the same as those from conventional Br?nsted acid catalysis, and in agreement with the Baldwin selectivity rules. Different mechanisms, however, should ultimately lead to new products, a promise anion–π catalysis has been reluctant to live up to. Herein, we report non-trivial reactions that work with anion–π catalysis, but not with Br?nsted acids, under comparable conditions. Namely, we show that the anion–π templated autocatalysis and epoxide opening with alcoholate–π interactions can provide access to unconventional ring chemistry. For smaller rings, anion–π catalysis affords anti-Baldwin oxolanes, 2-oxabicyclo[3.3.0]octanes, and the expansion of Baldwin oxetanes by methyl migration. For larger rings, anion–π templated autocatalysis is thought to alleviate the entropic penalty of folding to enable disfavored anti-Baldwin cyclizations into oxepanes and oxocanes.
3-(1H-PYRAZOL-4-YL)PYRIDINE ALLOSTERIC MODULATORS OF M4 MUSCARINIC ACETYLCHOLINE RECEPTOR
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, (2020/05/28)
Provided are cinnolinyl and quinolinyl pyrazol-4-yl-pyridine compounds which are allosteric modulators of the M4 muscarinic acetylcholine receptor, compositions comprising said compounds, and uses of said compounds in the treatment or prevention of diseases in which M4 muscarinic acetylcholine receptors are involved, especially neurological and psychiatric disorders and diseases.
3-(1H-PYRAZOL-4-YL)PYRIDINE ALLOSTERIC MODULATORS OF THE M4 MUSCARINIC ACETYLCHOLINE RECEPTOR
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, (2019/01/16)
The present invention is directed to pyrazol-4-yl-pyridine compounds which are allosteric modulators of the M4 muscarinic acetylcholine receptor. The present invention is also directed to uses of the compounds described herein in the potential treatment or prevention of neurological and psychiatric disorders and diseases in which M4 muscarinic acetylcholine receptors are involved. The present invention is also directed to compositions comprising these compounds. The present invention is also directed to uses of these compositions in the potential prevention or treatment of such diseases in which M4 muscarinic acetylcholine receptors are involved.
The palladium-catalyzed anti-Markovnikov hydroalkylation of allylic alcohol derivatives
DeLuca, Ryan J.,Sigman, Matthew S.
, p. 92 - 95 (2013/03/28)
A palladium-catalyzed hydroalkylation reaction of protected allylic alcohols using alkylzinc bromide reagents is reported. This account includes numerous allylic, homoallylic, and bishomoallylic alcohol derivatives, all with a uniform selectivity of >20:1
A stereoselective synthesis of the C9-C19 subunit of (+)-peloruside A
Raghavan, Sadagopan,Vinoth Kumar
, p. 2847 - 2858 (2013/05/08)
The stereoselective synthesis of a C9-C19 fragment of the potent antitumor agent peloruside A is disclosed. The C11 stereogenic centre was created by a vinylogous Mukaiyama aldol reaction following Carreira's protocol, with excellent stereocontrol. The C13 stereogenic centre was introduced by a substrate controlled reduction. The C15 stereocentre was fashioned using Noyori's asymmetric transfer hydrogenation while the Z-trisubstituted double bond was formed by a regioselective hydrostannation of an alkyne followed by methylation of the resultant vinyl stannane using Lipshutz's protocol. The C18 chiral centre was introduced by a chemoenzymatic route.
Lewis acid-promoted addition of 1,3-bis(silyl)propenes to aldehydes: A route to 1,3-dienes
Borg, Tessie,Tuzina, Pavel,Somfai, Peter
, p. 8070 - 8075 (2011/11/28)
The Lewis acid-promoted addition of 1,3-bis(silyl)-propenes to aldehydes to provide the corresponding (E)-1,3-dienes in excellent stereoselectivity and good to excellent yields is reported. The procedure is mild, base-free, and operationally straightforward.
Towards the synthesis of the 4,19-diol derivative of (-)-mycothiazole: Synthesis of a potential key intermediate
Batt, Frederic,Fache, Fabienne
, p. 6039 - 6055 (2011/12/15)
The synthesis of a potential key intermediate for the synthesis of the 4,19-diol derivative of (-)-mycothiazole using convergent strategies is described in this paper. Several approaches have been tested, including cross metathesis and a Julia-Kocienski olefination. Finally, the formation of the 1,1-dialkyl-1,2-ethanediol motif through C4-C5 bond construction was realized by nucleophilic addition of a vinyl iodide derivative to a keto ester after halogen/lithium exchange followed by reduction of the resulting hydroxy ester. The synthesis of the allylic 1,1-dialkyl-1,2-ethanediol group, achieved by halogen/metal exchange followed by addition to aα-keto ester, is the key step of this convergent strategy towards a potential intermediate of mycothiazole-4,19-diol.
NON-STEROIDAL PROGESTERONE RECEPTOR MODULATORS
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Page/Page column 38, (2008/12/07)
The present invention relates to non-steroidal progesterone receptor modulators of the general formula I, the use of the progesterone receptor modulators for the manufacture of medicaments, and pharmaceutical compositions which comprise these compounds. T
