77657-90-0Relevant articles and documents
Bioinspired Divergent Oxidative Cyclization from Strictosidine and Vincoside Derivatives: Second-Generation Total Synthesis of (?)-Cymoside and Access to an Original Hexacyclic-Fused Furo[3,2-b]indoline
Dou, Yingchao,Kouklovsky, Cyrille,Vincent, Guillaume
supporting information, p. 17190 - 17194 (2020/12/01)
The second-generation synthesis of (?)-cymoside as well as the formation of a new hexacyclic-fused furo[3,2-b]indoline framework is reported. After a Pictet–Spengler condensation between secologanin tetraacetate and tryptamine, the course of the cyclization of the 7-hydroxyindolenine intermediate, generated by oxidation with an oxaziridine, depended on the stereochemistry of the 3-position. The 3-(S)-strictosidine stereochemistry delivered efficiently the scaffold of cymoside via intramolecular coupling with the C16–C17 enol ether, while the 3-(R)-vincoside stereochemistry directed towards the reaction with the C18–C19 terminal alkene and the formation of the unexpected caged compound.
Dealkenylative Thiylation of C(sp3)-C(sp2) Bonds
Smaligo, Andrew J.,Kwon, Ohyun
supporting information, p. 8592 - 8597 (2019/10/14)
Carbon-carbon bond fragmentations are useful methods for the functionalization of molecules. The value of such cleavage events is maximized when paired with subsequent bond formation. Herein we report a protocol for the cleavage of an alkene C(sp3)-C(sp2) bond, followed by the formation of a new C(sp3)-S bond. This reaction is performed in nonanhydrous solvent and open to the air, employs common starting materials, and can be used to rapidly diversify natural products.
DIHYDROPYRONE COMPOUNDS AND HERBICIDES COMPRISING THE SAME
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Paragraph 0126, (2014/06/23)
The present invention provides a compound having an excellent efficacy for controlling weeds. A dihydropyrone compound of formula (I): wherein m is 1, 2 or 3; n is an integer of any one of 1 to 5; X represents O, S, S(O) or S(O)2; R1 /sup
Tandem reductive lithiations - Carbanionic cyclizations yielding sulfur stabilized cyclopropyl- and cyclobutylcarbinyllithiums
Chen, Fangping,Mudryk, Boguslaw,Cohen, Theodore
, p. 3291 - 3304 (2007/10/03)
Reductive lithiation of 1,4- or 1,5-bis(phenylthio)-1-alkenes with an aromatic radical-anion results in replacement with a lithium atom of only that phenylthio group which is attached to the sp3 carbon atom. The resulting carbanion executes an
1,5-Hydrogen transfers from carbon to N-tributyltin substituted nitrogen
Kim, Sunggak,Yeon, Kyu Man,Yoon, Kwang Sub
, p. 3919 - 3922 (2007/10/03)
1,5-H transfers from carbon to N-tributyltin substituted nitrogen proceeded smoothly and were much more efficient than 1,5-H transfers from carbon to ordinary nitrogen. 1,5-Tribuyltin group transfer from carbon to nitrogen and intramolecular addition of an aminyl radical to a nitrile group were also observed for the first time.
Asymmetric hydroformylations of sulfur-containing olefins catalyzed by BINAPHOS-Rh(I) complexes
Nanno,Sakai,Nozaki,Takaya
, p. 2583 - 2591 (2007/10/03)
Asymmetric hydroformylations of vinyl sulfides, allyl sulfides, and allyl sulfones catalyzed by (R,S)-BINAPHOS/Rh(acac)(CO2) afforded the corresponding branched oxo aldehydes as major products in 60-80% ee. Use of bulkier substituents on the sulfur in vinyl sulfides gave the branched oxo-aldehydes in higher regio- and enantioselectivities.
ION-RADICAL PROMOTED CYCLIZATION OF A δ,ε-VINYLIMINE: THE TOTAL SYNTHESIS OF (+/-)-TUBOXENINE
Cartier, Dominique,Ouahrani, Mohammed,Hugel, Georgette,Levy, Jean
, p. 657 - 662 (2007/10/02)
3-Oxo-1,2,18,19-tetradehydroaspidospermidine 8b was synthesized by a modification of a previous synthesis of vincadifformine 10.It was cyclized (Na/THF) to 3-oxotuboxenine 22, which was reduced with LiAlH4 to (+/-)-tuboxenine (1).
Elimination and Addition Reactions. Part 44. Eliminative Fission of Cycloalkanols
Bury, Adrian,Earl, Harold A.,Stirling, Charles J. M.
, p. 1281 - 1288 (2007/10/02)
Activation parameters for the fission of cyclopropanols and cyclobutanols with phenyl groups α or phenylthio or phenylsulphonyl groups β to the hydroxy group have been obtained.The results show very large differences in reactivity between cyclopropanols and cyclobutanols; such differences are also found in energy profiles for the opening of cycloalkoxide ions obtained by using MINDO3.The results are entirely compatible with other three-membered/four-membered ring comparisons and the role of strain in these systems is discussed.Attempts to extend the well established enforced catalysis of cycloalkanol ring fission to electrophiles other than Broensted acids have failed.
Synthesis of Lophotoxin Intermediate
Tius, Marcus A.,Trehan, Sanjay
, p. 765 - 767 (2007/10/02)
The carbometalation of an optically active homopropargyl alcohol is the key step in preparing the C-7, C-12 fragment of the marine neuromuscular agent (+)-lophotoxin.
APPROACHES TO THE SYNTHESIS OF ASPIDOSPERMA ALKALOIDS. PART II. THE SYNTHESIS OF 18,19-DIDEHYDROTABERSONINE.
Blowers, John W.,Saxton, J. Edwin,Swanson, Alistair G.
, p. 6071 - 6095 (2007/10/02)
The total synthesis of 18,19-dehydrotabersonine, via 3-oxo-18,19-didehydrovincadifformine, is described.
