64576-90-5Relevant academic research and scientific papers
Total synthesis of micropine and epimicropine
Bayquen, Aristea V.,Read, Roger W.
, p. 13467 - 13482 (1996)
The enantioselective total synthesis of micropine, an unusual 2,6-disubstituted piperidine alkaloid, and epimicropine, through mercuric trifluoroacetate-catalysed intramolecular alkenylamide cyclisation is described. The synthesis proceeds from L-serine and affords material of the same positive sign of optical rotation as the natural product thereby confirming the absolute stereochemistry of micropine.
Microconine [N-methyl-2-methyl-3-methoxy-6-(deca-l’,3′,5′-trienyl)piperidine, an alkaloid from Microcos paniculata]: Synthesis, stereochemistry and spectroscopic data
Davies, Stephen G.,Fletcher, Ai M.,Roberts, Paul M.,Taylor, Cameron E.,Thomson, James E.
supporting information, (2020/12/29)
Unambiguously corrected 1H NMR data for the originally isolated sample of microconine [N-methyl-2-methyl-3-methoxy-6-(deca-l’,3′,5′-trienyl)piperidine], an alkaloid found in Microcos paniculata, are reported. The asymmetric synthesis of the (2S,3R,6S)- and (2S,3S,6S)-stereoisomeric forms [epimeric at C(3)] of this compound allows the unambiguous assignment of the relative 2,3-cis-3,6-cis-configuration of the natural product. The synthesis uses the conjugate addition of enantiopure lithium (S)-N-benzyl-N-(α-methylbenzyl)amide to tert-butyl crotonate and ensuing enolate oxidation with (+)-camphorsulfonyloxaziridine to generate the requisite C(2) and C(3) stereogenic centres found within the target. After elaboration, an intramolecular reductive amination was used to form the piperidine ring, with concomitant formation of the C(6) stereogenic centre. Comparison of specific rotation data is consistent with the alkaloid having the absolute (2R,3R,6R)-configuration.
Oxidative cleavage of allyl ethers by an oxoammonium salt
Kelly, Christopher B.,Ovian, John M.,Cywar, Robin M.,Gosselin, Taylor R.,Wiles, Rebecca J.,Leadbeater, Nicholas E.
supporting information, p. 4255 - 4259 (2015/04/14)
A method to oxidatively cleave allyl ethers to their corresponding aldehydes mediated by an oxoammonium salt is described. Using a biphasic solvent system and mild heating, cleavage proceeds readily, furnishing a variety of α,β-unsaturated aldehydes and ketones.
Total synthesis of a piperidine alkaloid, microcosamine A
Raji Reddy, Chada,Latha, Bellamkonda,Warudikar, Kamalkishor,Singarapu, Kiran Kumar
supporting information, p. 251 - 258 (2015/12/30)
The first asymmetric total synthesis of a new natural piperidine alkaloid, microcosamine A, has been accomplished from d-serine and d-methyl lactate as chiral pool starting materials. Key features of the strategy include the utility of Horner-Wadsworth-Emmons reaction, Luche reduction, intramolecular carbamate N-alkylation to form the piperidine framework and Julia-Kocienski olefination to install the triene side-chain.
A short synthesis of conjugated unsaturated alcohols
Kazmaier, Uli
, p. 1491 - 1496 (2007/10/03)
Isomerization of acetylenic pentafluorophenyl esters in the presence of phosphines gives rise to activated dienoic esters, which can be reduced directly in a simple one pot procedure to the corresponding conjugated unsaturated alcohols 6-10. The higher reactivity of the pentafluorophenyl esters in comparison to alkyl esters allows their selective isomerization.
Novel Synthesis of Phenol Derivatives by Palladium-Catalyzed Cyclocarbonylation of 2,4-Pentadienyl Acetates
Ishii, Youichi,Gao, Chao,Xu, Wen-Xiang,Iwasaki, Masakazu,Hidai, Masanobu
, p. 6818 - 6825 (2007/10/02)
Phenyl acetates were selectively obtained in good yields by cyclocarbonylation of 2,4-pentadienyl acetates in the presence of NEt3, Ac2O, and a catalytic amount of palladium complexes such as PdCl2(PPh3)2 at 120-140 deg C under 50 atm of CO.No five-membered ring products were observed.A platinum complex PtCl2(PPh3)2 was also effective as a catalyst.The reaction of 5-phenyl-2,4-pentadienyl bromide with M(CO)(PPh3)3 (M = Pd or Pt) under CO gave the corresponding 6-phenyl-3,5-hexadienoyl complexes in a high yield, which in turn afforded 2-acetoxybiphenyl in 41-51percent yield on heating to 160 deg C under 50 atm of CO in the presence of NEt3 and Ac2O.Similar 3,5-hexadienoyl complexes are proposed to be intermediates in the catalytic cyclocarbonylation of 2,4-pentadienyl acetates.On the other hand, PdCl2(PPh3)2-catalyzed carbonylation of o-(bromomethyl)(1-alkenyl)benzenes in the presence of NEt3 and Ac2O gave 2-naphthyl acetates in moderate yields, while the reaction in the absence of Ac2O gave five-membered ring products such as 2-indanones or a tricyclic lactone by incorporation of one or two CO, respectively.
Synthesis of plastoquinone derivatives with different structures of the side chain
Liu, Benli,Gu, Lianquan,Zhang, Jingling
, p. 104 - 110 (2007/10/02)
Two schemes for the synthesis of plastoquinone derivatives with ω-substituted alkyl side chains have been developed, based on radical alkylation of 2,3-dimethyl-1,4-benzoquinone with ω-substituted carboxylic and/or dicarboxylic acids in the presence of S2O82- and Ag+.In Scheme 1, radical alkylation of 2,3-dimethyl-1,4-benzoquinone with 11-bromoundecanoic acid, in the presence of (NH4)2S2O8 and AgNO3, gave 2,3-dimethyl-5-(10-bromodecyl)-1,4-benzoquinone, which, after hydration, gave 2,3-dimethyl-5-(10-hydroxydecyl)-1,4-benzoquinone.Esterification of 2,3-dimethyl-5-(10-hydroxydecyl)-1,4-benzoquinone with different acyl chlorides gave 2,3-dimethyl-5-(10-acyloxydecyl)-1,4-benzoquinone.In Scheme 2, radical alkylation of 2,3-dimethyl-1,4-benzoquinone with adipic acid, in the presence of K2S2O8 and AgNO3, gave 2,3-dimethyl-5-(4-carboxybutyl)-1,4-benzoquinone, which was converted to 2,3-dimethyl-5--1,4-benzoquinone by esterification with different alcohols in the presence of dicyclohexylcarbodiimide. 2,3-Dimethyl-5-(8-carboxyoctyl)-1,4-benzoquinone and 2,3-dimethyl-5--1,4-benzoquinone were similarly synthesized from 2,3-dimethyl-1,4-benzoquinone and sebacic acid.Plastoquinone derivatives having different kinds of double bonds in the side chain with and without a 6-methyl group were synthesized from 2,3,5-trimethyl-1,4-benzoquinone and 2,3-dimethyl-1,4-benzoquinone by successive reactions with (1) NaBH4; (2) KHSO4, different kinds of allylic alcohols; (3) Ag2O.The allylic alcohols were prepared from their corresponding aldehydes by reduction with NaBH4. 2,3,6-Trimethyl-1,4-benzoquinone by radical methylation with acetic acids in the presence of K2S2O8 + AgNO3.
An approach to the synthesis of C18 tri-insaturated fatty acids.
Petragnani,Brocksom,Gato
, p. 627 - 634 (2007/10/12)
New approaches for the synthesis of cis, trans, trans, octadeca-9,11,13-trienoic acid (I) and its trans, trans, cis isomer (II), starting from the easily available propargyl alcohol are described.
