The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Takanori Suzuki - One of the best experts on this subject based on the ideXlab platform.
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Model studies for the stereoselective construction of the BC-ring of armatol F based on Ireland-Claisen rearrangement and relay ring-closing olefin metathesis
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Keita Tanaka, Yasushi Katagiri, Hidetoshi Kawai, Takanori SuzukiAbstract:Abstract Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a fused tricyclic ether moiety (BCD-ring) with an unusual cis ring junction at C18–C19 between the C- and D-rings. En route to the total synthesis of armatol F, the stereoselective construction of the C18 and C19 stereocenters by Ireland-Claisen rearrangement and the formation of the C-ring by relay ring-closing olefin metathesis were established through the synthesis of monocyclic (C-ring) and bicyclic (BC-ring) model compounds.
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Studies toward the total synthesis of armatol F: stereoselective construction of the C6 and C7 stereocenters and formation of the A-ring skeleton
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Hidetoshi Kawai, Yuta Hirose, Daisuke Sato, Takanori SuzukiAbstract:Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a solitary oxepane (A-ring) and a fused tricyclic ether moiety (BCD-ring). The A-ring features a rare cis-relationship between the hydroxy group at the quaternary carbon C6 and the carbon chain at C7. As part of our program toward the total synthesis of armatol F, a new stereoselective method for the construction of the C6 and C7 stereocenters has been developed based on chirality-transferring Ireland-Claisen rearrangement. The A-ring skeleton has also been synthesized from the rearrangement product by a process including ring-closing olefin metathesis.
Masaya Tani - One of the best experts on this subject based on the ideXlab platform.
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NeoChondria gen. nov. (Rhodomelaceae, Rhodophyta), a segregate of Chondria, including N. ammophila sp. nov. and N. nidifica comb. nov.
Phycologia, 2018Co-Authors: Suttikarn Sutti, Masaya Tani, Yukimasa Yamagishi, Tsuyoshi Abe, Kathy Ann Miller, Kazuhiro KogameAbstract:Abstract Using morphological and molecular evidence, we describe a new genus, NeoChondria, based on specimens formerly identified as ‘Chondria tenuissima' sensu Okamura in Japan. The generitype, NeoChondria ammophila sp. nov., is not closely related to Chondria capillaris (Hudson) M.J. Wynne, the generitype of Chondria. The anatomy of NeoChondria differs from that of Chondria by the development of adventitious elongate cells between the five major pericentral cells, forming densely compact layers surrounding the axial strand, even in the ultimate branchlets. We propose the new combination, NeoChondria nidifica, based on Chondria nidifica Harvey from California, USA and Baja California, Mexico. Multigene analyses (rbcL, small subunit and cox1) and morphological observations demonstrated that N. ammophila and N. nidifica share a clade but preliminary results show that they may not belong in the tribe Chondrieae.
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A taxonomic study of two minute species of Chondria (Ceramiales, Rhodophyta) from the north-western Pacific, with the description of Chondria econstricta sp. nov.
Phycologia, 2003Co-Authors: Masaya Tani, Michio MasudaAbstract:Abstract Morphological features of two minute species of the red algal genus Chondria (Rhodomelaceae, Ceramiales) from the north-western Pacific are described. Chondria xishaensis is characterized by the following features: (1) the axes continue to grow while producing reproductive structures (the axes begin to form reproductive structures when they are 2 mm in length, and reach 17 mm); (2) only one of the five pericentral cells in each segment produces a tetrasporangium. In C. econstricta Tani & Masuda sp. nov.: (1) the axes are prostrate and up to 25 mm long; (2) the axes and branches are terete, and their tips are usually truncate and form an apical pit; (3) the branches (except for young adventitious branches) lack constricted bases; (4) cell wall thickenings are absent; (5) the subsurface cells form irregular transverse rows alternating with wide spaces; (6) the orbicular spermatangial plates are depressed and possess a single row (or rarely, partially two rows) of sterile marginal cells; (7) the cys...
Kenshu Fujiwara - One of the best experts on this subject based on the ideXlab platform.
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Model studies for the stereoselective construction of the BC-ring of armatol F based on Ireland-Claisen rearrangement and relay ring-closing olefin metathesis
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Keita Tanaka, Yasushi Katagiri, Hidetoshi Kawai, Takanori SuzukiAbstract:Abstract Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a fused tricyclic ether moiety (BCD-ring) with an unusual cis ring junction at C18–C19 between the C- and D-rings. En route to the total synthesis of armatol F, the stereoselective construction of the C18 and C19 stereocenters by Ireland-Claisen rearrangement and the formation of the C-ring by relay ring-closing olefin metathesis were established through the synthesis of monocyclic (C-ring) and bicyclic (BC-ring) model compounds.
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Studies toward the total synthesis of armatol F: stereoselective construction of the C6 and C7 stereocenters and formation of the A-ring skeleton
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Hidetoshi Kawai, Yuta Hirose, Daisuke Sato, Takanori SuzukiAbstract:Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a solitary oxepane (A-ring) and a fused tricyclic ether moiety (BCD-ring). The A-ring features a rare cis-relationship between the hydroxy group at the quaternary carbon C6 and the carbon chain at C7. As part of our program toward the total synthesis of armatol F, a new stereoselective method for the construction of the C6 and C7 stereocenters has been developed based on chirality-transferring Ireland-Claisen rearrangement. The A-ring skeleton has also been synthesized from the rearrangement product by a process including ring-closing olefin metathesis.
Michio Masuda - One of the best experts on this subject based on the ideXlab platform.
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A taxonomic study of two minute species of Chondria (Ceramiales, Rhodophyta) from the north-western Pacific, with the description of Chondria econstricta sp. nov.
Phycologia, 2003Co-Authors: Masaya Tani, Michio MasudaAbstract:Abstract Morphological features of two minute species of the red algal genus Chondria (Rhodomelaceae, Ceramiales) from the north-western Pacific are described. Chondria xishaensis is characterized by the following features: (1) the axes continue to grow while producing reproductive structures (the axes begin to form reproductive structures when they are 2 mm in length, and reach 17 mm); (2) only one of the five pericentral cells in each segment produces a tetrasporangium. In C. econstricta Tani & Masuda sp. nov.: (1) the axes are prostrate and up to 25 mm long; (2) the axes and branches are terete, and their tips are usually truncate and form an apical pit; (3) the branches (except for young adventitious branches) lack constricted bases; (4) cell wall thickenings are absent; (5) the subsurface cells form irregular transverse rows alternating with wide spaces; (6) the orbicular spermatangial plates are depressed and possess a single row (or rarely, partially two rows) of sterile marginal cells; (7) the cys...
Hidetoshi Kawai - One of the best experts on this subject based on the ideXlab platform.
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Model studies for the stereoselective construction of the BC-ring of armatol F based on Ireland-Claisen rearrangement and relay ring-closing olefin metathesis
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Keita Tanaka, Yasushi Katagiri, Hidetoshi Kawai, Takanori SuzukiAbstract:Abstract Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a fused tricyclic ether moiety (BCD-ring) with an unusual cis ring junction at C18–C19 between the C- and D-rings. En route to the total synthesis of armatol F, the stereoselective construction of the C18 and C19 stereocenters by Ireland-Claisen rearrangement and the formation of the C-ring by relay ring-closing olefin metathesis were established through the synthesis of monocyclic (C-ring) and bicyclic (BC-ring) model compounds.
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Studies toward the total synthesis of armatol F: stereoselective construction of the C6 and C7 stereocenters and formation of the A-ring skeleton
Tetrahedron Letters, 2010Co-Authors: Kenshu Fujiwara, Hidetoshi Kawai, Yuta Hirose, Daisuke Sato, Takanori SuzukiAbstract:Armatol F, isolated from the red alga Chondria armata as a polyether triterpene, has a solitary oxepane (A-ring) and a fused tricyclic ether moiety (BCD-ring). The A-ring features a rare cis-relationship between the hydroxy group at the quaternary carbon C6 and the carbon chain at C7. As part of our program toward the total synthesis of armatol F, a new stereoselective method for the construction of the C6 and C7 stereocenters has been developed based on chirality-transferring Ireland-Claisen rearrangement. The A-ring skeleton has also been synthesized from the rearrangement product by a process including ring-closing olefin metathesis.