A new synthesis of lactones: application to (±)-mevalonolactone

Fétizon, M.; Golfier, M.; Louis, Jean-Marie

doi:10.1039/c29690001118

Cited by 48 publications

(17 citation statements)

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“…Transformation of C-5 hydroxymethyl analogues 4 into dibenzylbutryolactone lignans 1 was achieved via reduction using LiAlH 4 , to the corresponding triols 38aa – bd , followed by periodate cleavage, forming lactols 39aa – bd . These lactols 39aa – bd were then oxidised using Fetizon’s reagent [37,38] to give racemic samples of dibenzyl butyrolactone lignans 1aa – bd , including known natural products arcitin 1aa , bursehernin 1ab , (3 R* ,4 R* )-3-(3″,4″-dimethoxybenzyl)-4-(3′,4′,5′-trimethoxybenzyl)dihydrofuran-2(3 H )-one 1ac , kusunokinin 1ba , hinokinin 1bb, and isoyatein 1bc . Additionally, phenolic lignans, buplerol 1ae , and haplomyrfolin 1be were produced by the debenzylation of 1ad and 1bd , respectively.…”

Section: Resultsmentioning

confidence: 99%

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

et al. 2018

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Dibenzyl butyrolactone lignans are well known for their excellent biological properties, particularly for their notable anti-proliferative activities. Herein we report a novel, efficient, convergent synthesis of dibenzyl butyrolactone lignans utilizing the acyl-Claisen rearrangement to stereoselectively prepare a key intermediate. The reported synthetic route enables the modification of these lignans to give rise to 5-hydroxymethyl derivatives of these lignans. The biological activities of these analogues were assessed, with derivatives showing an excellent cytotoxic profile which resulted in programmed cell death of Jurkat T-leukemia cells with less than 2% of the incubated cells entering a necrotic cell death pathway.

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Section: Resultsmentioning

confidence: 99%

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

et al. 2018

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“…Selective double resonance was used to assign the C-8 and C-9 methyl carbons and the syn-group (C-8) proved to be the less shielded one, contrary to proton spectra where the opposite is true. 61 The proton shift difference is only 8 Hz at 60 MHz and room temperature in a concentrated CS2 solution, but this was just enough for selective decoupling.…”

Section: Camphor (39)mentioning

confidence: 99%

Carbon‐13 chemical shifts of bicyclic compounds

Lippmaa¹,

Pehk²,

Paasiv́irta

et al. 1970

Org. Magn. Reson.

162

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Abstract-"C NMR absorption spectra of 50 bicyclic hydrocarbons, alcohols and ketones have been measured, in addition to some terpenes. The "C chemical shifts are approximately additive for similar compounds and can be used for the determination of molecular structure; they differ for endo-and exo-isomers, just as in proton spectra. These quite regular and predictable I3C shift differences are much larger and are caused by the 1,4-nonbonded interaction between atoms heavier than hydrogen, not by magnetic anisotropy effects. I N T R O D U C T I O N BICYCLO [2.2.1 IHEPTANE ring systems (derivatives of norbornane and norbornene)are rigid molecules of known and fixed geometry that have been very actively investigated by proton resonance methods' to " in order to study the influence of molecular geometry and polar substituents on proton chemical shifts and coupling constants. The general applicability of the Karplus relationships between vicinal proton-proton coupling constants and dihedral anglesz8 and the 'W-letter' rule for couplings between distant protons,z9 as well as the linear variation of vicinal coupling constants with substituent electronegativities,' were all conclusively demonstrated on these and similar systems.' These relationships have been extremely useful in elucidating the structures of bicyclic and polycyclic compounds, particularly for the determination of substituent orientations. In addition to coupling constants, proton chemical shifts and their differences have been found to correlate well with molecular structure. It has been found that further to the usual inductive effects which are most apparent on the a-proton, many other analytically significant effects are present. F r a~e r ,~ M u~h e r ,~ and Paasivirta3 have pointed out that exo-protons in norbornane and norbornene derivatives are deshielded relative to the endo-protons at the same carbon atom. Additionally, in 2-substituted norbornanes the 24x0-proton of the endo-isomer is deshielded relative to the 2-endo-proton of the exo-i~omer.'~ This effect is similar to the well-known chemical shift difference between the diamagnetic axial and paramagnetic equatorial protons in cyclohexane derivative^.^' Shift differences of this kind have generally been attributed to the diamagnetic anisotropy of the double bond or to the magnetic effect of the adjacent single bonds respectively. Similarly, substituents in the 2-and 3-positions cause a chemical shift difference of protons at the double bond." A 2-or 3-endo-substituent leads to an increased shift difference of the 5-and 6-protons across the ring. This effect can be partially explained by the substituent anisotropy effect, but the influence of a -€N group is smaller than that of -OH and a good fit of the shifts with known group anisotropies could not be a~h i e v e d .~ Likewise, the shieldings of the 7-syn and 7-anti protons are not equal, the 7-anti proton being the more shielded one.',' This result was at first unexpected, and Tori et al. in their first paper6 assigned the 7-syn proton to the...

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“…Hz, l H , CHOAc), 5.14 (dd, 3J = 6.8/1.9 Hz, IH, CHOAc). -I3C NMR: 6 = 20.9, 21.08 (CH3), 25.4,25.9,26.2,29.8,32.07,3,4,6,7,8),41.2,45.5,48.4,5,9,12),80.9,ll),170.3,170.6 (CO) 4, 25.2, 25.5, 29.1, 31.36, 31.40 (C-2,3,4,6,7,8), 40.2, 45.2, 49.6, 49.8 (C-1,5,9,12), 79.6, 86.4 (C-10,ll …”

Section: Discussion Of the X-ray Structuresmentioning

confidence: 99%

Synthesis of Stereoisomeric Ufolanes

et al. 1992

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Three of the six possible stereoisomers of dodecahydroacenaphthylene, f,t,t-ufolane (l), c,c,f-ufolane (3), and c,c,c-ufolane The names derived from the IUPAC nomenclature rules for the six possible stereoisomers 1 -6 are quite long. Therefore, we propose the following simple notation: For the dodecahydroacenaphthylenes with trans-linkage of all rings, viz. for 1, we have already proposed the name "ufolane"['ol. This name will now be used for all stereoisomers of dodecakydroacenapktkylene. For the notation of the configuration we follow the rules of Landa and Vanek?1. The molecules are drawn in such a way that the fivemembered ring is at the top.2. The hydrogen at the central tertiary carbon atom lies above the paper.3. The relation of the carbon -hydrogen bond at the central tert. carbon atom to the carbon-hydrogen bonds at the other tert. carbon atom is characterized as cis or trans, beginning with C-1 (unsystematic numbering) and continuing clockwise.4. In addition to the rules of Landa and Vanek@] we propose: If there are two possibilities following rule 3 the direction is: cis precedes trans, e.g. the correct name for 3 will be rac-cis,cis,trans-ufolane or -abbreviated -rac-c,c,tufolane and not rac-trans,cis,cis-ufolane (rac-t,c,c-ufolane) as drawn in 3a, if the racemate and not a specific enantiomer is to be indicated.c,c,c-Ufolane (5) seems to be the most valuable isomer with respect to its use as a propellant because of its high mass density.Vanek et aLc6] showed that five isomers are formed by catalytic hydrogenation of acenaphthene; the authors separated them by thermodiffusion and isolated one by preparative GC. The isomers were characterized by means of their G C retention indicesr5a6]. Furthermore, the assignment of the structure of the five isomers was attempted on the basis of their 13C-NMR spectral"] or of the G C retention indices on columns with graphitized thermal carbon black['*'. However, an unequivocal structural assignment was still lacking. We describe here the synthesis of the three stereoisomers 1, 3, and 5. Scheme IChem.

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A new synthesis of lactones: application to (±)-mevalonolactone

Cited by 48 publications

References 0 publications

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

Modular Synthesis and Biological Investigation of 5-Hydroxymethyl Dibenzyl Butyrolactones and Related Lignans

Carbon‐13 chemical shifts of bicyclic compounds

Synthesis of Stereoisomeric Ufolanes

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