133. Physical properties and chemical constitution. Part XVI. Ethylenic compounds

Jeffery, George H.; Vogel, Arthur I.

doi:10.1039/jr9480000658

Cited by 43 publications

(12 citation statements)

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“…A new synthesis of 2-pyrones has been developed. Two molecules of a,P-unsaturated acid chlorides (8, 12 and 18) condense, with loss of two molecules hydrogen chloride, to pairs of substituted 2-pyrones (9 and 10, 13 and 14, 19 and 20) when treated with triethyl amine in chloroform or methylene chloride at room temperature. In the case of 18, two additional products were obtained, namely the resorcinol derivative 21 and traces of the 1,3-cyclobutanedione derivative 22. Under the same conditions the a,B-unsaturated acid chlorides 8,15,18 and 41 were condensed with tIichloroacety1 chloride to give 6-trichloromethyl-2-pyrones (42, 43, 44 and 46).…”

Section: Cis-35-dimethyzcyczopentenmentioning

confidence: 99%

“…Die Reaktion der 6-Trichlormethyl-2-pyrone mit Zink in Eisessig, welche die entsprechenden 6-methylsubstituierten 2-Pyrone liefert, wird in einer anderen Arbeit [14] beschrieben. [19] ; trans-2-Pentcnsaurechlorid (40), aus trans-2-Pentensaure und Thionylchlorid ; Geranoylsaurechlorid (41), aus Geranoylsaure6) und Thionylchlorid [ZO]. Das Triathylamin wurde uber Natriumhydrid destilliert.…”

Section: L)unclassified

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Synthesen von 2‐Pyronen aus α, β‐ungesättigten Säurechloriden und tertiären Aminen

Rey

Dunkelblum

Allain

et al. 1970

Helvetica Chimica Acta

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A new synthesis of 2‐pyrones has been developed. Two molecules of α, β‐unsaturated acid chlorides (8, 12 and 18) condense, with loss of two molecules hydrogen chloride, to pairs of substituted 2‐pyrones (9 and 10, 13 and 14, 19 and 20) when treated with triethyl amine in chloroform or methylene chloride at room temperature. In the case of 18, two additional products were obtained, namely the resorcinol derivative 21 and traces of the 1, 3‐cyclobutanedione derivative 22. Under the same conditions the α, β‐unsaturated acid chlorides 8, 15, 18 and 41 were condensed with trichloroacetyl chloride to give 6‐trichloromethyl‐2‐pyrones (42, 43, 44 and 46). These 2‐pyrones are valuable intermediates for the synthesis of 6‐carboxy‐2‐pyrones and 6‐methyl‐2‐pyrones. A methyl group in β‐position of the α, β‐unsaturated acid chloride appears to be essential for the described condensations, for the acid chlorides 16 and 17 did not yield defined products and the acid chloride 40 reacted with trichloroacetyl chloride in a very low yield. It is considered that the described reactions proceed via the 1, 4‐addition of an acid chloride to a vinyl ketene or through the acylation of an intermediate anion by an acyl derivative as outlined in reaction scheme 1. The structures of the 2‐pyrones were confirmed by their spectroscopic properties, summarized in table 3, and by some of their chemical transformations.

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Section: Cis-35-dimethyzcyczopentenmentioning

confidence: 99%

Section: L)unclassified

Synthesen von 2‐Pyronen aus α, β‐ungesättigten Säurechloriden und tertiären Aminen

Rey

Dunkelblum

Allain

et al. 1970

Helvetica Chimica Acta

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“…The b,g-unsaturated allylester 27 [32] was deprotonated at À 78 8C in THF with LiHMDS (Scheme 5). Addition of Me 3 SiCl, warming to reflux temperature, and an aqueous work-up [33] followed, giving a quantitative yield of crude carboxylic acids.…”

Section: Resultsmentioning

confidence: 99%

Total Syntheses of (−)-Grandinolide and (−)-Sapranthin by the Sharpless Asymmetric Dihydroxylation of Methyltrans-3-Pentenoate: Elucidation of the Stereostructure of (−)-Sapranthin

1998

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Methyl trans-3-pentenoate (7) was converted into the cis-substituted g-lactone 8 in a single step with 78 % ee. The derived enolate dilithio-8 was alkylated trans-selectively with primary iodoalkanes. with 1-iodobutane dilithio-8 afforded, after esterification with isovaleroyl chloride, the epi-blastmycinone 9. Dilithio-8 gave (À)-grandinolide (11) with 1-iodo-19-phenylnonadecane (20). A third trans-selective alkylation of dilithio-8 was undertaken with 16-iodo-1,5-hexadecadiene-7,9-diyne (21). This gave the g-lactone 12, which had the published relative configuration of (À)-sapranthin but different spectroscopic data. When the OH group of lactone 8 was inverted (to hydroxylactone 40) and the derived enolate dilithio-40 alkylated with iodide 21, lactone 41 resulted. Its 1 H and 13 C NMR spectra and the sign and value of optical rotation coincide with the data of natural sapranthin. These findings establish that (À)-sapranthin possesses the relative and absolute configuration of stereoformula 41.

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“…Dimethyl 2-allylmalonate was prepared by the procedure in [12] and diphenylphosphine oxide, by the procedure in [13]. Dimethyl 2-allylmalonate was prepared by the procedure in [12] and diphenylphosphine oxide, by the procedure in [13].…”

Section: -[3-(diphenylphosphinoyl)propyl]-2-thiobarbituric Acid (Vi)mentioning

confidence: 99%

10.1007/s11176-008-2025-7

2010

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133. Physical properties and chemical constitution. Part XVI. Ethylenic compounds

Cited by 43 publications

References 1 publication

Synthesen von 2‐Pyronen aus α, β‐ungesättigten Säurechloriden und tertiären Aminen

Synthesen von 2‐Pyronen aus α, β‐ungesättigten Säurechloriden und tertiären Aminen

Total Syntheses of (−)-Grandinolide and (−)-Sapranthin by the Sharpless Asymmetric Dihydroxylation of Methyltrans-3-Pentenoate: Elucidation of the Stereostructure of (−)-Sapranthin

10.1007/s11176-008-2025-7

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