Hisanaka Ito

Co-reporter:Hideki Abe, Yuta Ogura, Toyoharu Kobayashi, and Hisanaka Ito

Organic Letters November 3, 2017 Volume 19(Issue 21) pp:5996-5996

Publication Date(Web):October 17, 2017

DOI:10.1021/acs.orglett.7b03038

The first total synthesis of tricyclic bisnorsesquiterpene paralemnolide A, isolated from the soft coral Paralemnalia thyrsoides, was achieved. This synthesis features the lactonization of the cyclohexene derivative having a tert-butyl ester via stereoselective epoxidation followed by treatment with a Brønsted acid and construction of the novel tricyclic skeleton by an intramolecular Reformatsky–Honda reaction.

Total synthesis of pleurolactone

Co-reporter:Toyoharu Kobayashi, Masako Ishida, Kazuhiro Imaida, Hideki Abe, Hisanaka Ito

Tetrahedron Letters 2017 Volume 58, Issue 33(Issue 33) pp:

Publication Date(Web):16 August 2017

DOI:10.1016/j.tetlet.2017.07.028

•Total synthesis of a menthane-type monoterpenoid pleurolactone is achieved.•The construction of four contiguous stereocenters on the hexahydrobenzofuran core.•Endo-selective Diels-Alder reaction.•High stereoselective dihydroxylation.The stereoselective total synthesis of pleurolactone has been accomplished in 7 steps. The key synthetic features were the construction of four contiguous stereocenters using an endo-selective Diels-Alder reaction and high diastereoselective dihydroxylation.Download high-res image (137KB)Download full-size image

Diastereoselective Total Synthesis of (±)-Toxicodenane A

Co-reporter:Toyoharu Kobayashi;Kotono Yamanoue;Hideki Abe

European Journal of Organic Chemistry 2017 Volume 2017(Issue 45) pp:6693-6699

Publication Date(Web):2017/12/08

DOI:10.1002/ejoc.201701219

The first total synthesis of tricyclic sesquiterpene (±)-toxicodenane A has been accomplished. This synthetic work was completed in 12 steps from dimedone through diastereoselective reductive desymmetrization of 2,2-disubstituted 5,5-dimethylcyclohexane-1,3-dione, stereocontrolled allylation, ring-closing metathesis of a diene compound to yield bicyclic compounds that bear a seven-membered ring, and construction of the oxygen-bridged moiety through neighboring group assisted ring-opening reaction of an epoxide as key steps.

Asymmetric total synthesis and revision of absolute configurations of azaphilone derivative felinone A

Co-reporter:Hideki Abe, Haruhito Tango, Toyoharu Kobayashi, Hisanaka Ito

Tetrahedron Letters 2017 Volume 58, Issue 45(Issue 45) pp:

Publication Date(Web):8 November 2017

DOI:10.1016/j.tetlet.2017.09.090

•Asymmetric total synthesis of azaphilone derivative felinone A was accomplished.•The absolute configuration of felinone A was revised.•Construction of the dihydropyrane ring by intramolecular oxymercuration/demercuration.The first total synthesis of the azaphilone derivative, felinone A, was accomplished. The absolute configuration of natural felinone A was revised to be 3S, 6S, and 7R.Download high-res image (126KB)Download full-size image

Catalytic asymmetric total synthesis of (+)-artalbic acid

Co-reporter:Toyoharu Kobayashi, Ryuta Shioi, Ai Ushie, Hideki Abe and Hisanaka Ito

Chemical Communications 2016 vol. 52(Issue 60) pp:9391-9393

Publication Date(Web):30 Jun 2016

DOI:10.1039/C6CC04828E

The first total synthesis of (+)-artalbic acid has been accomplished using asymmetric allylation of an acetoacetate derivative with a phase-transfer catalyst. This synthetic work was completed in 12 steps from isopropyl acetoacetate with high stereocontrol. In addition, the absolute configuration of naturally occurring artalbic acid was determined to be 7S, 9S, and 10S.

The Total Synthesis of ()-Naupliolide: A Tetracyclic Sesquiterpene Lactone

Co-reporter:Dr. Hideki Abe;Tomoyuki Morishita;Toshihiro Yoshie;Kérya Long;Dr. Toyoharu Kobayashi ; Hisanaka Ito

Angewandte Chemie International Edition 2016 Volume 55( Issue 11) pp:3795-3798

Publication Date(Web):

DOI:10.1002/anie.201600055

Abstract

The first total synthesis of (±)-naupliolide has been achieved. The synthetic method includes a Simmons–Smith cyclopropanation of an allyl alcohol, diastereoselective cleavage of a benzylidene acetal group, radical cyclization of an aldehyde with a cyclopropane ring, and construction of an eight-membered ring by ring-closing metathesis.

The Total Synthesis of ()-Naupliolide: A Tetracyclic Sesquiterpene Lactone

Co-reporter:Dr. Hideki Abe;Tomoyuki Morishita;Toshihiro Yoshie;Kérya Long;Dr. Toyoharu Kobayashi ; Hisanaka Ito

Angewandte Chemie 2016 Volume 128( Issue 11) pp:3859-3862

Publication Date(Web):

DOI:10.1002/ange.201600055

Abstract

The first total synthesis of (±)-naupliolide has been achieved. The synthetic method includes a Simmons–Smith cyclopropanation of an allyl alcohol, diastereoselective cleavage of a benzylidene acetal group, radical cyclization of an aldehyde with a cyclopropane ring, and construction of an eight-membered ring by ring-closing metathesis.

Total synthesis of the proposed structure of a polyketide from Phialomyces macrosporus

Co-reporter:Hideki Abe, Satoko Itaya, Kei Sasaki, Toyoharu Kobayashi and Hisanaka Ito

Chemical Communications 2015 vol. 51(Issue 17) pp:3586-3589

Publication Date(Web):22 Jan 2015

DOI:10.1039/C5CC00129C

Total synthesis of the proposed structure of a polyketide isolated from Phialomyces macrosporus is described. The synthesis involved chemoselective epoxidation, regioselective epoxide ring opening, chemo- and diastereoselective dihydroxylation, and vinylation of lactone accompanied by the formation of a furan ring.

Stereoselective synthesis of a highly oxygenated decahydrocyclopenta[g]chromene derivative: the common tricyclic framework of leucosceptrine and leucosesterterpenone

Co-reporter:Hideki Abe, Yuri Horii, Megumi Hagiwara, Toyoharu Kobayashi and Hisanaka Ito

Chemical Communications 2015 vol. 51(Issue 28) pp:6108-6110

Publication Date(Web):27 Feb 2015

DOI:10.1039/C5CC00879D

Stereoselective construction of the highly oxygenated decahydrocyclopenta[g]chromene skeleton, which is the tricyclic core of leucosceptrine, which possesses prolylendopeptidase inhibitory activity, and leucosesterterpenone, which exhibits anti-angiogenic activity, from Leucosceptrum canum, was achieved.

Directed synthesis of 2-spiroindolines from indole derivatives by formic acid-induced N-acyliminium ion-conjugated diene spirocyclization

Co-reporter:Hideki Abe, Naohiro Miyagawa, Sho Hasegawa, Toyoharu Kobayashi, Sakae Aoyagi, Chihiro Kibayashi, Tadashi Katoh, Hisanaka Ito

Tetrahedron Letters 2015 Volume 56(Issue 7) pp:921-924

Publication Date(Web):11 February 2015

DOI:10.1016/j.tetlet.2014.12.130

Synthesis of 2-spiroindolines from 2-substituted indole derivatives via acid-induced N-acyliminium ion-conjugated diene spirocyclization was demonstrated. This methodology can be used to direct transformations of 2-substituted indole moieties into 3-nonsubstituted-2-spiroindoline skeletons.

Synthetic study of marine diterpenoid aberrarone: stereocontrolled construction of tetracyclic framework

Co-reporter:Toyoharu Kobayashi, Kasumi Tokumoto, Yuki Tsuchitani, Hideki Abe, Hisanaka Ito

Tetrahedron 2015 Volume 71(Issue 35) pp:5918-5924

Publication Date(Web):2 September 2015

DOI:10.1016/j.tet.2015.05.089

Highly stereocontrolled synthesis of the tetracyclic framework of the marine diterpenoid aberrarone, which possesses antimalarial activity against a chloroquine-resistant strain of Plasmodium, has been accomplished. A key feature of the synthesis is the complete stereocontrolled construction of C- and D-ring using stereoselective 1,4-addition followed by intramolecular aldol reaction protocol.

Concise Total Synthesis of Albaflavenone Utilizing Sequential Intramolecular Aldol Condensation: Determination of Absolute Configuration

Co-reporter:Toyoharu Kobayashi, Yutaro Kon, Hideki Abe, and Hisanaka Ito

Organic Letters 2014 Volume 16(Issue 24) pp:6397-6399

Publication Date(Web):December 3, 2014

DOI:10.1021/ol503202d

The first total synthesis of albaflavenone, a novel antibiotic sesquiterpene, has been accomplished via the concise construction of its zizaene skeleton utilizing sequential intramolecular aldol condensation followed by chemo- and diastereoselective reduction of the conjugated carbon–carbon double bond. This synthetic work was completed in nine steps from 2-cyclopenten-1-one as a starting material without the use of protecting groups and with high stereocontrol. In addition, the absolute configuration of naturally occurring albaflavenone was determined to be 1R,2S and 8S.

Concise Total Synthesis of Spirocurcasone

Co-reporter:Hideki Abe, Akimi Sato, Toyoharu Kobayashi, and Hisanaka Ito

Organic Letters 2013 Volume 15(Issue 6) pp:1298-1301

Publication Date(Web):February 28, 2013

DOI:10.1021/ol400228v

A concise total synthesis of spirocurcasone was accomplished. Key features of the synthesis involved a vinylogous Mukaiyama aldol reaction, a Carroll rearrangement of β-keto allyl ester derivative, an intramolecular aldol condensation, and a spiro ring formation by ring-closing metathesis of the pentaene compound. This synthetic work was complete in nine steps from (S)- or (R)-perillaldehyde without the use of protecting groups. Interestingly, the optical rotation of the synthetic spirocurcasone was different from the reported value of the natural product.

Indium chloride mediated chlorolactonization: construction of chlorinated lactone fragments

Co-reporter:Hideki Abe, Naoki Fukazawa, Toyoharu Kobayashi, Hisanaka Ito

Tetrahedron 2013 69(12) pp: 2519-2523

Publication Date(Web):

DOI:10.1016/j.tet.2013.01.072

Synthetic study of yonarolide: stereoselective construction of the tricyclic core

Co-reporter:Yohei Ueda, Hideki Abe, Kazuo Iguchi, Hisanaka Ito

Tetrahedron Letters 2011 Volume 52(Issue 26) pp:3379-3381

Publication Date(Web):29 June 2011

DOI:10.1016/j.tetlet.2011.04.092

Stereoselective construction of the tricyclic core of yonarolide (1), a marine norditerpenoid, was achieved. This synthetic route includes a Diels–Alder reaction and an intramolecular aldol condensation. It also involves efficient epimerization through a retro-Michael reaction–Michael addition and will be applicable to the total synthesis of 1.

Concise asymmetric total synthesis of catunaregin

Co-reporter:Hideki Abe, Takuma Hikichi, Kosuke Emori, Toyoharu Kobayashi and Hisanaka Ito

Inorganic Chemistry Frontiers 2016 - vol. 3(Issue 9) pp:NaN1086-1086

Publication Date(Web):2016/06/28

DOI:10.1039/C6QO00213G

The asymmetric total synthesis of catunaregin isolated from the Chinese mangrove is described. The synthesis involves an asymmetric syn-selective aldol reaction and the successive ketalization of a furan diol derivative under acidic conditions. This methodology is very concise and highly stereoselective. The asymmetric total synthesis of the optically pure catunaregin was accomplished in 7 steps from a known methyl ester.

Total synthesis of the proposed structure of a polyketide from Phialomyces macrosporus

Co-reporter:Hideki Abe, Satoko Itaya, Kei Sasaki, Toyoharu Kobayashi and Hisanaka Ito

Chemical Communications 2015 - vol. 51(Issue 17) pp:NaN3589-3589

Publication Date(Web):2015/01/22

DOI:10.1039/C5CC00129C

Total synthesis of the proposed structure of a polyketide isolated from Phialomyces macrosporus is described. The synthesis involved chemoselective epoxidation, regioselective epoxide ring opening, chemo- and diastereoselective dihydroxylation, and vinylation of lactone accompanied by the formation of a furan ring.

Catalytic asymmetric total synthesis of (+)-artalbic acid

Co-reporter:Toyoharu Kobayashi, Ryuta Shioi, Ai Ushie, Hideki Abe and Hisanaka Ito

Chemical Communications 2016 - vol. 52(Issue 60) pp:NaN9393-9393

Publication Date(Web):2016/06/30

DOI:10.1039/C6CC04828E

The first total synthesis of (+)-artalbic acid has been accomplished using asymmetric allylation of an acetoacetate derivative with a phase-transfer catalyst. This synthetic work was completed in 12 steps from isopropyl acetoacetate with high stereocontrol. In addition, the absolute configuration of naturally occurring artalbic acid was determined to be 7S, 9S, and 10S.

Stereoselective synthesis of a highly oxygenated decahydrocyclopenta[g]chromene derivative: the common tricyclic framework of leucosceptrine and leucosesterterpenone

Co-reporter:Hideki Abe, Yuri Horii, Megumi Hagiwara, Toyoharu Kobayashi and Hisanaka Ito

Chemical Communications 2015 - vol. 51(Issue 28) pp:NaN6110-6110

Publication Date(Web):2015/02/27

DOI:10.1039/C5CC00879D

Stereoselective construction of the highly oxygenated decahydrocyclopenta[g]chromene skeleton, which is the tricyclic core of leucosceptrine, which possesses prolylendopeptidase inhibitory activity, and leucosesterterpenone, which exhibits anti-angiogenic activity, from Leucosceptrum canum, was achieved.

TOPICS

Abstract

Abstract