Progress Toward the Asymmetric de Novo Synthesis of Lanostanes: A Counter Biomimetic Cucurbitane-to-Lanostane Type Transformation
Tetrahedron. 2023 Jul 17;141:133498. doi: 10.1016/j.tet.2023.133498. Epub 2023 Jun 2.ABSTRACTAn oxidative rearrangement has been established that enables a cucurbitane-to-lanostane type rearrangement that is counter to known biomimetic transformations that proceed in an opposite direction by way of a lanostane-to-cucurbitane transformation. Here, an oxidative dearomatization/Wagner-Meerwein rearrangement with a substrate bearing the characteristic cucurbitane triad of quaternary centers at C9, C13 and C14, and possessing an alkene at C11-C12, proceeds in a manner that selectively shifts the methyl group at C9 to C10 in con...
Source: Tetrahedron - August 28, 2023 Category: Chemistry Authors: Andrea R Bucknam Glenn C Micalizio Source Type: research
Progress Toward the Asymmetric de Novo Synthesis of Lanostanes: A Counter Biomimetic Cucurbitane-to-Lanostane Type Transformation
Tetrahedron. 2023 Jul 17;141:133498. doi: 10.1016/j.tet.2023.133498. Epub 2023 Jun 2.ABSTRACTAn oxidative rearrangement has been established that enables a cucurbitane-to-lanostane type rearrangement that is counter to known biomimetic transformations that proceed in an opposite direction by way of a lanostane-to-cucurbitane transformation. Here, an oxidative dearomatization/Wagner-Meerwein rearrangement with a substrate bearing the characteristic cucurbitane triad of quaternary centers at C9, C13 and C14, and possessing an alkene at C11-C12, proceeds in a manner that selectively shifts the methyl group at C9 to C10 in con...
Source: Tetrahedron - August 28, 2023 Category: Chemistry Authors: Andrea R Bucknam Glenn C Micalizio Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
A Biaryl-Cyclohexenone Photoelectrocyclization/Dearomatization Sequence to Substituted Terpenes
Tetrahedron. 2023 Jan 26;131:133180. doi: 10.1016/j.tet.2022.133180. Epub 2022 Dec 10.ABSTRACTDescribed here is the development of sequential cross-coupling, photoelectrocyclizations, and reductive dearomatizations of biaryl cyclohexenones as a means of synthesizing terpene skeletons. This methodology promises to provide insight that will enable us and others to use this approach to generate a variety of biologically active small molecules, including members of the abietane and morphinan skeletons.PMID:37593114 | PMC:PMC10430876 | DOI:10.1016/j.tet.2022.133180 (Source: Tetrahedron)
Source: Tetrahedron - August 18, 2023 Category: Chemistry Authors: K S Satyanarayana Tummalapalli Xuchen Zhao Jon D Rainier Source Type: research
The Analysis of Two Distinct Strategies toward the Enantioselective Formal Total Synthesis of (+)-Gelsenicine
Tetrahedron. 2023 Mar 21;134:133278. doi: 10.1016/j.tet.2023.133278. Epub 2023 Jan 21.ABSTRACTA full account of a formal enantioselective total synthesis of (+)-gelsenicine is described. Separate strategies based on catalytic cycloisomerization as the central step are considered. One plan involves chirality transfer from enantioenriched substrates, while the other employs asymmetric catalysis. The chirality transfer strategy is less effective, while in the latter, phosphoramidite- and bisphosphine-gold complexes are tested and ultimately provide a key intermediate in high enantiopurity in our Gelsemium alkaloid syntheses.P...
Source: Tetrahedron - April 10, 2023 Category: Chemistry Authors: Haofan Ji Phil C Knutson Christopher M Harrington Yan-Ting Ke Eric M Ferreira Source Type: research
Synthesis of 4- < em > O < /em > -(4-Amino-4-deoxy- β-D-xylopyranosyl)paromomycin and 4- < em > S < /em > -( β-D-Xylopyranosyl)-4-deoxy-4'-thio-paromomycin and Evaluation of their Antiribosomal and Antibacterial Activity
Tetrahedron. 2023 Apr 6;135:133330. doi: 10.1016/j.tet.2023.133330. Epub 2023 Feb 23.ABSTRACTThe design, synthesis and antiribosomal and antibacterial activity of two novel glycosides of the aminoglycoside antibiotic paromomycin are described. The first carries of 4-amino-4-deoxy-β-D-xylopyranosyl moiety at the paromomycin 4'-position and is approximately two-fold more active than the corresponding β-D-xylopyranosyl derivative. The second is a 4'-(β-D-xylopyranosylthio) derivative of 4'-deoxyparomomycin that is unexpectedly less active than the simple β-D-xylopyranosyl derivative, perhaps because of the insertion of th...
Source: Tetrahedron - April 10, 2023 Category: Chemistry Authors: Rukshana Mohamad-Ramshan Chennaiah Ande Takahiko Matsushita Klara Haldimann Andrea Vasella Sven N Hobbie David Crich Source Type: research
The Analysis of Two Distinct Strategies toward the Enantioselective Formal Total Synthesis of (+)-Gelsenicine
Tetrahedron. 2023 Mar 21;134:133278. doi: 10.1016/j.tet.2023.133278. Epub 2023 Jan 21.ABSTRACTA full account of a formal enantioselective total synthesis of (+)-gelsenicine is described. Separate strategies based on catalytic cycloisomerization as the central step are considered. One plan involves chirality transfer from enantioenriched substrates, while the other employs asymmetric catalysis. The chirality transfer strategy is less effective, while in the latter, phosphoramidite- and bisphosphine-gold complexes are tested and ultimately provide a key intermediate in high enantiopurity in our Gelsemium alkaloid syntheses.P...
Source: Tetrahedron - April 10, 2023 Category: Chemistry Authors: Haofan Ji Phil C Knutson Christopher M Harrington Yan-Ting Ke Eric M Ferreira Source Type: research
Synthesis of 4- < em > O < /em > -(4-Amino-4-deoxy- β-D-xylopyranosyl)paromomycin and 4- < em > S < /em > -( β-D-Xylopyranosyl)-4-deoxy-4'-thio-paromomycin and Evaluation of their Antiribosomal and Antibacterial Activity
Tetrahedron. 2023 Apr 6;135:133330. doi: 10.1016/j.tet.2023.133330. Epub 2023 Feb 23.ABSTRACTThe design, synthesis and antiribosomal and antibacterial activity of two novel glycosides of the aminoglycoside antibiotic paromomycin are described. The first carries of 4-amino-4-deoxy-β-D-xylopyranosyl moiety at the paromomycin 4'-position and is approximately two-fold more active than the corresponding β-D-xylopyranosyl derivative. The second is a 4'-(β-D-xylopyranosylthio) derivative of 4'-deoxyparomomycin that is unexpectedly less active than the simple β-D-xylopyranosyl derivative, perhaps because of the insertion of th...
Source: Tetrahedron - April 10, 2023 Category: Chemistry Authors: Rukshana Mohamad-Ramshan Chennaiah Ande Takahiko Matsushita Klara Haldimann Andrea Vasella Sven N Hobbie David Crich Source Type: research
The Analysis of Two Distinct Strategies toward the Enantioselective Formal Total Synthesis of (+)-Gelsenicine
Tetrahedron. 2023 Mar 21;134:133278. doi: 10.1016/j.tet.2023.133278. Epub 2023 Jan 21.ABSTRACTA full account of a formal enantioselective total synthesis of (+)-gelsenicine is described. Separate strategies based on catalytic cycloisomerization as the central step are considered. One plan involves chirality transfer from enantioenriched substrates, while the other employs asymmetric catalysis. The chirality transfer strategy is less effective, while in the latter, phosphoramidite- and bisphosphine-gold complexes are tested and ultimately provide a key intermediate in high enantiopurity in our Gelsemium alkaloid syntheses.P...
Source: Tetrahedron - April 10, 2023 Category: Chemistry Authors: Haofan Ji Phil C Knutson Christopher M Harrington Yan-Ting Ke Eric M Ferreira Source Type: research
