Synthesis of 2,3-Dihydrothiopyran-4-ones from 3-Oxo-1-pentene-4-ynes

Rosiak, Anna; Müller, Ralf; Christoffers, Jens

doi:10.1007/s00706-006-0571-4

“…34 The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6. 27,35 ynal 19 could undergo the addition of 1-propynylmagnesium bromide (9) to give expected aryl-hexa-1,4-diyn-3-ol 15 with a yield of 89%. 11 The last step before the cyclization in γpyrone was the oxidation of 15 to corresponding ketone 20 using MnO 2 .…”

Section: Resultsmentioning

confidence: 99%

“…After regioselective bromination with NBS (Scheme , compound 7 ) and protection of phenolic function, MOM-protected bromoguaiacol was obtained with an overall yield of 90% (Scheme , compound 17 ). − Then, Sonogashira coupling using propargyl alcohol ( 8 ) in the presence of palladium complex catalyst as well as copper cocatalyst led to butynyl alcohol derivative 18 in good yield . The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6 . , ynal 19 could undergo the addition of 1-propynylmagnesium bromide ( 9 ) to give expected aryl-hexa-1,4-diyn-3-ol 15 with a yield of 89% . The last step before the cyclization in γ-pyrone was the oxidation of 15 to corresponding ketone 20 using MnO 2 . , Thus, according to this synthetic way γ-pyrone’s precursor 20 was obtained with an overall yield of 66%.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric γ-Pyrone, an Analogue of Cyclocurcumin

Pecourneau

¹

,

Losantos

²

,

Monari

³

et al. 2021

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Cyclocurcumin (CC), a turmeric curcuminoid with potential therapeutic properties, is also a natural photoswitch that may undergo E/Z photoisomerization under UV light. To be further exploited in relevant biological applications, photoactivation under near-infrared (NIR) irradiation is required. Such requirement can be met through opportune chemical modifications, by favoring two-photon absorption (TPA) probability. Herein, a general and efficient synthesis of a biomimetic 2,6disubstituted-γ-pyrone analogue of CC is described, motivated by the fact that molecular modeling previews an order of magnitude increase of its NIR TPA compared to CC. Three retrosynthetic pathways have been identified (i) via an aryl-oxazole intermediate or via aryl-diynone through (ii) a bottom-up or (iii) a top-down approach. While avoiding the passage through unstable synthons or low-yield intermediate reactions, only the latest approach could conveniently afford the 2,6-disubstituted-γ-pyrone analogue of CC, in ten steps and with an overall yield of 18%. The photophysical properties of our biomimetic analogue have also been characterized showing an improved photoisomerization yield over the parent natural compound. The potentially improved nonlinear optical properties, as well as enhanced stability, may be correlated to the enforcement of the planarity of the pyrone moiety leading to a quadrupolar D−π−A−π−D system.

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“…34 The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6. 27,35 The ynone 19 could undergo the addition of 1-propynylmagnesium bromide (9) to give the expected aryl-hexa-1,4-diyn-3-ol 15 with a yield of 89%. 11 The last step before the cyclization in g-pyrone was the oxidation of 15 in corresponding ketone 20 using MnO2.…”

Section: Synthesis Of 26-g-pyrone Analogue Of Cyclocurcuminmentioning

confidence: 99%

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric 2,6-Gamma-Pyrone, Analogue of Cyclocurcumin

Pecourneau¹,

Losantos²,

Monari³

et al. 2021

Preprint

View full text Add to dashboard Cite

Cyclocurcumin, a turmeric curcuminoid with potential therapeutic properties, is also a natural photoswitch that may undergo E/Z photoisomerization under UV light. In order to be further exploited in relevant biological applications, photoactivation under near infrared (NIR) irradiation is required. Such requirement can be met through opportune chemical modifications,and most notably by favoring two-photon absorption (TPA) probability. Herein, a general and efficient synthesis of a biomimetic 2,6-g-pyrone analogue of cyclocurcumin is described, motivated by the fact that molecular modeling previews an order of magnitude increase of the NIR TPA cross-section for the latter compared to the natural counterpart. Three retrosynthetic pathways have been identified (i) via an aryl-oxazole intermediate or via an aryl-diynone through (ii) a bottom-up or (iii) a top-down approach. While avoiding the passage through unstable synthons or low yield intermediate reactions, only the latest approach could conveniently afford the 2,6-g-pyrone analogue of cyclocurcumin, in ten steps and with an overall yield of 18%. The photophysical properties of our biomimetic analogue have also been characterized showing an improved photo-isomerization yield over the parent natural compound. The potentially improved non-linear optical properties, as well an enhanced stability, may be correlated to the enforcement of the planarity of the pyrone moiety leading to a quadrupolar D-p-A-p-D system.<br>

show abstract

“…34 The oxidation with an excess of manganese dioxide gave aldehyde 19 which did not exhibit the instability of 6. 27,35 The ynal 19 could undergo the addition of 1-propynylmagnesium bromide (9) to give the expected aryl-hexa-1,4-diyn-3-ol 15 with a yield of 89%. 11 The last step before the cyclization in g-pyrone was the oxidation of 15 in corresponding ketone 20 using MnO2.…”

Section: Scheme 3 Synthetic Pathway To Obtain Terminal Alkynementioning

confidence: 99%

Synthesis and photoswitching properties of bioinspired dissymmetric gamma-pyrone, analogue of cyclocurcumin

Pecourneau¹,

Losantos²,

Monari

³

et al. 2021

Preprint

View full text Add to dashboard Cite

Cyclocurcumin, a turmeric curcuminoid with potential therapeutic properties, is also a natural photoswitch that may undergo E/Z photoisomerization under UV light. In order to be further exploited in relevant biological applications, photoactivation under near infrared (NIR) irradiation is required. Such requirement can be met through opportune chemical modifications,and most notably by favoring two-photon absorption (TPA) probability. Herein, a general and efficient synthesis of a biomimetic 2,6-g-pyrone analogue of cyclocurcumin is described, motivated by the fact that molecular modeling previews an order of magnitude increase of the NIR TPA cross-section for the latter compared to the natural counterpart. Three retrosynthetic pathways have been identified (i) via an aryl-oxazole intermediate or via an aryl-diynone through (ii) a bottom-up or (iii) a top-down approach. While avoiding the passage through unstable synthons or low yield intermediate reactions, only the latest approach could conveniently afford the 2,6-g-pyrone analogue of cyclocurcumin, in ten steps and with an overall yield of 18%. The photophysical properties of our biomimetic analogue have also been characterized showing an improved photo-isomerization yield over the parent natural compound. The potentially improved non-linear optical properties, as well an enhanced stability, may be correlated to the enforcement of the planarity of the pyrone moiety leading to a quadrupolar D-p-A-p-D system.<br>

show abstract

Synthesis of 2,3-Dihydrothiopyran-4-ones from 3-Oxo-1-pentene-4-ynes

Cited by 16 publications

References 7 publications

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric γ-Pyrone, an Analogue of Cyclocurcumin

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric γ-Pyrone, an Analogue of Cyclocurcumin

Synthesis and Photoswitching Properties of Bioinspired Dissymmetric 2,6-Gamma-Pyrone, Analogue of Cyclocurcumin

Synthesis and photoswitching properties of bioinspired dissymmetric gamma-pyrone, analogue of cyclocurcumin

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