27301-54-8Relevant academic research and scientific papers
Total synthesis of 2′-O-methylmyxalamide D and (6E)-2′-O- methylmyxalamide D
Coleman, Robert S.,Lu, Xiaoling,Modolo, Isabelle
, p. 3826 - 3827 (2007)
Hetero-bis-metalated 1,3,5-hexatrienes are employed in the linchpin coupling of synthetic fragments for the convergent construction of the central pentaene of the antifungal agent 2′-O-methylmyxalamide D and its (6E) isomer. Sequential Stille and Suzuki-Miyaura couplings interpolate the boron/tin triene into the pentaene chain. The total synthesis of O-methylmyxalamide D and its (6E) isomer was accomplished efficiently. Copyright
Vibrational spectra, conformations, ab initio calculations and vibrational assignments of 3-pentyn-2-ol
Horn, Anne,Klaeboe, Peter,Nielsen, Claus J.,Guirgis, Gamil A.
, p. 102 - 112 (2008)
The infrared spectra of 3-pentyn-2-ol, CH3C{triple bond, long}CCH(OH)CH3, have been recorded as a vapour and liquid at ambient temperature, as a solid at 78 K in the 4000-50 cm-1 range and isolated in an argon matrix at ca. 5 K. Infrared spectra of the solid phase at 78 K were obtained before and after annealing to temperatures of 120 and 130 K. The IR spectra of the solid were quite similar to that of the liquid. Raman spectra of the liquid were recorded at room temperature and at various temperatures between 295 and 153 K. Spectra of an amorphous and annealed solid were recorded at 78 K. In the variable temperature Raman spectra, some bands changed in relative intensity and were interpreted in terms of conformational equilibria between the three possible conformers. Complete assignments were made for all the bands of the most stable conformer in which OH is oriented anti to C1(aMe). From various bands assigned to a second conformer in which OH is oriented anti to Hgem(aH), the conformational enthalpy differences was found to be between 0.4 and 0.8 kJ mol-1. The highest energy conformer with OH anti to C3(aC) was not detected. Quantum-chemical calculations have been carried out at the MP2 and B3LYP levels with a variety of basis sets. Except for small basis set calculations for which the aH conformer had slightly lower energy, all the calculations revealed that aMe was the low energy conformer. The B3LYP/cc-pVTZ calculations suggested the aMe conformer as more stable by 0.8 and 8.3 kJ mol-1 relative to aH an aC, respectively. Vibrational wavenumbers and infrared and Raman band intensities for two of the three conformers are reported from B3LYP/cc-pVTZ calculations.
Convenient generation of 1-propynyllithium. One-pot synthesis of acetylenic carbinols from 1,2-dibromopropane and aldehydes and ketones
Gribble,Joyner,Switzer
, p. 2997 - 3002 (1992)
Treatment of 1,2-dibromopropane (1) with 3 equiv of lithium diisopropylamide (-60° to 0°C, THF) generates 1-propynyllithium (2), which with aldehydes or ketones affords acetylenic carbinols 3 in 82-96% yields.
Spectroscopy and Photochemistry of Triplet 1,3-Dimethylpropynylidene (MeC3Me)
Knezz, Stephanie N.,Waltz, Terese A.,Haenni, Benjamin C.,Burrmann, Nicola J.,McMahon, Robert J.
, p. 12596 - 12604 (2016)
Photolysis (λ > 472 nm) of 2-diazo-3-pentyne (11) affords triplet 1,3-dimethylpropynylidene (MeC3Me, 33), which was characterized spectroscopically in cryogenic matrices. The infrared, electronic absorption, and electron paramagnetic resonance spectra of MeC3Me (33) are compared with those of the parent system (HC3H) to ascertain the effect of alkyl substituents on delocalized carbon chains of this type. Quantum chemical calculations (CCSD(T)/ANO1) predict an unsymmetrical equilibrium structure for triplet MeC3Me (33), but they also reveal a very shallow potential energy surface. The experimental IR spectrum of triplet MeC3Me (33) is best interpreted in terms of a quasilinear, axially symmetric structure. EPR spectra yield zero-field splitting parameters that are typical for triplet carbenes with axial symmetry (|D/hc| = 0.63 cm-1, |E/hc| = β 0 cm-1), while theoretical analysis suggests that the methyl substituents confer significant spin polarization to the carbon chain. Upon irradiation into the near-UV electronic absorption (λmax 350 nm), MeC3Me (33) undergoes 1,2-hydrogen migration to yield pent-1-en-3-yne (4), a photochemical reaction that is typical of carbenes bearing a methyl substituent. This facile process apparently precludes photoisomerization to other interesting C5H6 isomers, in contrast to the rich photochemistry of the parent C3H2 system.
Synthesis and characterization of all four diastereomers of 3,4-dichloro-2-pentanol, motifs relevant to the chlorosulfolipids
Kanady, Jacob S.,Nguyen, John D.,Ziller, Joseph W.,Vanderwal, Christopher D.
, p. 2175 - 2178 (2009)
All four diastereomers of 3,4-dichloro-2-pentanol were synthesized by anti-dichlorination of the precursor allylic alcohols; their stereochemistry was elucidated by X-ray crystallographic analysis of tosylate derivatives. Complete NMR data is provided in
Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis
Chen, Violet Yijang,Kwon, Ohyun
supporting information, p. 8874 - 8881 (2021/03/17)
Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael–Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.
Stereoselective Synthesis of the C1-C22 Carbon Framework of (-)-Amphidinolide K
Chandankar, Somnath S.,Raghavan, Sadagopan
, p. 9584 - 9602 (2019/09/06)
Two stereoselective routes to the C7-C22 subunit of amphidinolide K are disclosed. Jacobsen's hydrolytic kinetic resolution and Sharpless' asymmetric dihydroxylation reactions have been employed for the construction of the tetrahydrofuran ring. The C10-C1
Propene as an Atom-Economical Linchpin for Concise Total Synthesis of Polyenes: Piericidin A
Trost, Barry M.,Gholami, Hadi
supporting information, p. 11623 - 11626 (2018/09/21)
A concise and convergent total synthesis of piericidin A is disclosed. The synthesis hinges on the utilization of propene as a synthetic linchpin to merge the properly elaborated alkyne fragments, leading to the 1,3,6-triene motif of piericidin A. Utilization of propene as a unique alkene, capable of sequential coupling with two alkynes, is further illustrated in the context of various 1,3,6-triene products. The latter process proceeds with high atom economy and efficiently gives rise to complex frameworks from readily accessible alkyne substrates. This strategic C-C bond formation offers an orthogonal paradigm in the design of synthetic routes, leading to higher step economy and more efficient syntheses of polyunsaturated natural products.
MACROCYCLIC PICOLINAMIDES AS FUNGICIDES
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Paragraph 0098; 0099, (2016/01/25)
This disclosure relates to macrocyclic picolinamides of Formula (I) described herein, wherein X, Y, R1 and R2 are as defined herein and to their use as fungicides in a formulation comprising a phytologically acceptable carrier. Also provided are methods of using compounds of Formula (I) in combination with other pesticides including fungicides, insecticides, nematocides, miticides, arthropodicides, bactericides, and combinations thereof.
Torquoselectivity in the nazarov reactions of allenyl vinyl ketones
Morgan, Timothy D. R.,Leblanc, Luc M.,Ardagh, Giselle H.,Boyd, Russell J.,Burnell, D. Jean
, p. 1042 - 1051 (2015/01/30)
Nazarov reactions mediated by BF3-etherate of a series of carbon-substituted allenyl vinyl ketones provided intermediates in which substituents on the termini of the allenes had rotated away from the vinyl moieties, and these intermediates were
