The Experts below are selected from a list of 1758 Experts worldwide ranked by ideXlab platform
Akitami Ichihara - One of the best experts on this subject based on the ideXlab platform.
-
total syntheses of cepaciamides a and b novel fungitoxic 3 amino 2 piperidinone containing lipids produced by pseudomonas cepacia d 202
Tetrahedron, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Total syntheses of cepaciamides A and B were accomplished (R)-3-Amino-2-piperidinone was obtained via cyclization of (R)-ornithine. The common amide-linked fatty acid was synthesized via Sharpless AD as the key step. Amide-formation was achieved with DEPC. In the preparation of two fatty acid segments, (S)-malic acid was used as the chiral source to introduce (2S)-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of (Z)-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between the fatty acid-segments and the amide-segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
-
study on fungitoxic 3 amino 2 piperidinone containing lipids total syntheses of cepaciamides a and b
Tetrahedron Letters, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Abstract Total syntheses of cepaciamides A and B were accomplished. In the preparation of two fatty acid segments, ( S )-malic acid was used as a chiral source to introduce ( 2S )-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of ( Z )-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between fatty acid segments and amide segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
Hiroaki Toshima - One of the best experts on this subject based on the ideXlab platform.
-
total syntheses of cepaciamides a and b novel fungitoxic 3 amino 2 piperidinone containing lipids produced by pseudomonas cepacia d 202
Tetrahedron, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Total syntheses of cepaciamides A and B were accomplished (R)-3-Amino-2-piperidinone was obtained via cyclization of (R)-ornithine. The common amide-linked fatty acid was synthesized via Sharpless AD as the key step. Amide-formation was achieved with DEPC. In the preparation of two fatty acid segments, (S)-malic acid was used as the chiral source to introduce (2S)-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of (Z)-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between the fatty acid-segments and the amide-segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
-
study on fungitoxic 3 amino 2 piperidinone containing lipids total syntheses of cepaciamides a and b
Tetrahedron Letters, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Abstract Total syntheses of cepaciamides A and B were accomplished. In the preparation of two fatty acid segments, ( S )-malic acid was used as a chiral source to introduce ( 2S )-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of ( Z )-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between fatty acid segments and amide segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
Masatoshi Saito - One of the best experts on this subject based on the ideXlab platform.
-
total syntheses of cepaciamides a and b novel fungitoxic 3 amino 2 piperidinone containing lipids produced by pseudomonas cepacia d 202
Tetrahedron, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Total syntheses of cepaciamides A and B were accomplished (R)-3-Amino-2-piperidinone was obtained via cyclization of (R)-ornithine. The common amide-linked fatty acid was synthesized via Sharpless AD as the key step. Amide-formation was achieved with DEPC. In the preparation of two fatty acid segments, (S)-malic acid was used as the chiral source to introduce (2S)-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of (Z)-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between the fatty acid-segments and the amide-segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
-
study on fungitoxic 3 amino 2 piperidinone containing lipids total syntheses of cepaciamides a and b
Tetrahedron Letters, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Abstract Total syntheses of cepaciamides A and B were accomplished. In the preparation of two fatty acid segments, ( S )-malic acid was used as a chiral source to introduce ( 2S )-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of ( Z )-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between fatty acid segments and amide segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
Kazuko Maru - One of the best experts on this subject based on the ideXlab platform.
-
total syntheses of cepaciamides a and b novel fungitoxic 3 amino 2 piperidinone containing lipids produced by pseudomonas cepacia d 202
Tetrahedron, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Total syntheses of cepaciamides A and B were accomplished (R)-3-Amino-2-piperidinone was obtained via cyclization of (R)-ornithine. The common amide-linked fatty acid was synthesized via Sharpless AD as the key step. Amide-formation was achieved with DEPC. In the preparation of two fatty acid segments, (S)-malic acid was used as the chiral source to introduce (2S)-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of (Z)-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between the fatty acid-segments and the amide-segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
-
study on fungitoxic 3 amino 2 piperidinone containing lipids total syntheses of cepaciamides a and b
Tetrahedron Letters, 1999Co-Authors: Hiroaki Toshima, Kazuko Maru, Masatoshi Saito, Akitami IchiharaAbstract:Abstract Total syntheses of cepaciamides A and B were accomplished. In the preparation of two fatty acid segments, ( S )-malic acid was used as a chiral source to introduce ( 2S )-configuration. A known chiral Cyclopropane Derivative was introduced in the segment of cepaciamide A. The formation of ( Z )-olefin in the segment of cepaciamide B was achieved by means of partial reduction of the acetylenic bond. Esterification between fatty acid segments and amide segment with DCC/DMAP and subsequent oxidative deprotection of the MPM group with CAN gave cepaciamides.
Lesage Denis - One of the best experts on this subject based on the ideXlab platform.
-
Gold- and platinum-catalyzed cycloisomerization of enynyl esters versus allenenyl esters : an experimental and theoretical study
'Wiley', 2009Co-Authors: Marion Nicolas, Lemiere Gilles, Correa Andrea, Costabile Chiara, Ramon, Ruben S, Moreau Xavier, De Fremont Pierre, Dahmane Rim, Hours Alexandra, Lesage DenisAbstract:Experimental and theoretical studies on Au- and Pt-catalyzed cycloisomerization of a branched dienyne with an acetate group at the propargylic position are presented. The peculiar architecture of the dienyne precursor, which has both a 1,6- and a 1,5-enyne skeleton, leads, in the presence of alkynophilic gold catalysts, to mixtures of bicyclic compounds 3, 4, and 5. Formation of unprecedented bicyclo[3.1.0]hexene 5 is the main focus of this study. The effect of the ancillary ligand on the gold center was examined and found to be crucial for formation of 5. Further mechanistic studies, involving cyclization of an enantioenriched dienyne precursor, O-18-labeling experiments, and DFT calculations, allowed an unprecedented reaction pathway to be proposed. We show that bicyclo[3.1.0]hexene 5 is likely formed by a 1,3-OAc shift/allene-ene cyclization/1,2-OAc shift sequence, as calculated by DFT and supported by Au-catalyzed cyclization of isolated allenenyl acetate 7, which leads to improved selectivity in the formation of 5. Additionally, the possibility of OAc migration from allenyl acetates was supported by a trapping experiment with styrene that afforded the corresponding Cyclopropane Derivative. This unprecedented generation of a vinyl metal carbene from an allenyl ester supports a facile enynyl ester/allenenyl ester equilibrium. Further examination of the difference in reactivity between enynyl acetates and their corresponding [3,3]-rearranged allenenyl acetates toward Au- and Pt-catalyzed cycloisomerization is also presented
