Exceptionally easy isomerization of acetylenic alcohols with potassium 3-aminopropylamide. A new, high yield synthesis of functionally differentiated αω-difunctional structures

Brown, Charles A.; Yamashita, Akihiro

doi:10.1039/c39760000959

Cited by 46 publications

(13 citation statements)

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“…The product was then deprotected using K 2 CO 3 in MeOH to give the target terminal alkyne 20. . 34 Since allenes are known to undergo isomerization to alkynes when treated with strong bases, as in the alkyne zipper reaction, [35][36][37] we decided to continue the synthesis using allene 26.…”

Section: Scheme 3 Preparation Of Vinyl Triflatementioning

confidence: 99%

“…Before trying the isomerization of the allene using standard methods, 35,36 it was decided to investigate if it was possible to form the nine-membered ring compound 29 di-rectly from the allene 19 (Scheme 9). Strong bases are known to induce the isomerization of allenes to terminal alkynes.…”

Section: Scheme 8 Preparation Of Aldehyde 19mentioning

confidence: 99%

“…After the unsuccessful attempts of in situ isomerization of the allene to the terminal alkyne, we tried to conduct the reaction following standard methods: Potassium 3-aminopropylamide (KAPA) is the most commonly used base to induce the alkyne zipper reaction, which forms the terminal alkyne very fast at 0°C. 35,36 We tried the isomerization on three different substrates; compounds 27, 32, and 36, the last compound being prepared by TBS protection of tertiary alcohol 27 (Scheme 10). Compounds 27, 32, and 36 were treated at 0°C or room temperature at different concentration of KAPA 37 and reaction times.…”

Section: Scheme 8 Preparation Of Aldehyde 19mentioning

confidence: 99%

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Synthetic Studies on the Sporolides: Exploration of the Enediyne Route

Bonazzi¹,

Binaghi²,

Fellay³

et al. 2009

Synthesis

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Synthetic studies towards the construction of the cyclopenta[a]indene fragment of the heptacyclic marine metabolite sporolide are reported based on a hypothetical biosynthesis. The key step of this biogenetic proposal includes a Bergman cyclization of an enediyne precursor. The enediyne target of this synthetic study was prepared by Sonogashira cross-coupling of two fragments, of which the cyclopentane fragment was prepared from cyclopentenone, Morita-Baylis-Hillman reaction, and enantioselective Sharpless dihydroxylation.

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Section: Scheme 3 Preparation Of Vinyl Triflatementioning

confidence: 99%

Section: Scheme 8 Preparation Of Aldehyde 19mentioning

confidence: 99%

Section: Scheme 8 Preparation Of Aldehyde 19mentioning

confidence: 99%

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Synthetic Studies on the Sporolides: Exploration of the Enediyne Route

Bonazzi¹,

Binaghi²,

Fellay³

et al. 2009

Synthesis

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“…per reaction 6 before protection of the alcohol of 5 as the tert -butyldimethylsilyl ether (92%). This protecting group is stable to subsequent conditions used to build the diene systems and is removed under nonacidic conditions without isomerization of the double bonds.…”

mentioning

confidence: 99%

Stereospecific Synthesis of (E,Z)- and (Z,Z)-Hexadeca-10,12-dienal. Sex Pheromone Components of Diaphania hyalinata

Cabezas¹,

Oehlschlager²

1999

Synthesis

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Isomeric ( E , Z )-and ( Z , Z )-hexadeca-10,12-dienal were prepared, stereospecifically, in 51% and 43% overall yields from dec-1-yne.Diaphania hyalinata and Diaphania nitidalis are pyralid species that exhibit similar life cycles and habits. The former feeds upon the foliage of pumpkin and other cucurbits, 2 whereas the latter is particularly destructive to cantaloupe, cucumber and muskmelon. 3 The damage caused make these crops unsuitable for marketing. The isomers ( E , Z )-hexadeca-10,12-dienal (1) and ( Z , Z )-hexadeca-10,12-dienal (2) were isolated, as minor components, from the extracts of ovipositors of female melonworm, D. hyalinata , 2 while trace amounts of 1 were found in extracts from pickleworm adults of D. nitidalis . 3 These compounds, along with others, represent essential components of the sex pheromones of these species. Previous syntheses of the ( E , Z )-isomer 1 have involved Wittig condensation of butyltriphenylphosphorane with ( E )-12-(2-tetrahydropyranyloxy)dodec-2-enal, 4 followed by oxidation. The major drawback of this procedure is the generation of a mixture of E and Z isomers in the Wittig reaction. The ( Z , Z )-isomer has been prepared by the Ca-diotÐChodkiewicz coupling of pent-1-yne with undec-10yn-1-ol, followed by reduction of the triple bond with dicyclohexylborane to the corresponding dienol. 2 The alcohols ( E , Z )-and ( Z , Z )-hexadeca-10,12-dien-1-ol have been synthesized stereospecifically, by the palladium-catalyzed cross-coupling reaction between an hydroxyalkenylborane and the appropriate haloalkene in the presence of a base. 5 The overall %yields reported for the syntheses of these alcohols, from undec-10-en-1-ol, are 41 and 27% respectively. 5 In this paper we report stereospecific syntheses of the isomeric dienals 1 and 2 in 51 and 43% overall yields from dec-1-yne (3) . The syntheses utilized the common precursor tert -butyldimethylsilyl undec-10-ynyl ether (6) which was prepared from dec-1-yne (3) by coupling of its lithium acetylide with paraformaldehyde, at low temperature, to give undec-2-yn-1-ol ( 4 ) in 93% (Scheme 1). The latter was isomerized to undec-10-yn-1-ol (5) in 98% by a zip-Stereospecific Synthesis of ( E , Z )-and ( Z , Z )-Hexadeca-10,12-dienal.

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“…tive thermodynamic stabilities of the components. The discovery of the ''acetylenic zipper" reacIt has been suggested that in cases where the base tion has widened the scope of base mediated dkyne is the salt of a diamine such as ethylenediamine (4) is~merizations ( 5 , [10][11][12]. Using a very strong or 1,3-diaminopropane (9, the base may be able to base, the potassium salt of 1,3-diaminopropane abstract and donate a proton in a cyclic fashion (DAP) in DAP, the migration of a triple bond more (Scheme 1).…”

mentioning

confidence: 99%

The rearrangement of isomeric linear decyn-1-ols by reaction with the sodium salt of 1,3-diaminopropane

Macaulay¹

1980

Can. J. Chem.

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This paper is dedicated to Prof. Raymond U . Lemieux on the occasion of his 60th birthday SUZANNE R. MACAULAY. Can. J. Chem. 58, 2567Chem. 58, (1980. Isomerization of straight chain decyn-1-01s mediated by the sodium salt of 1,3-diaminopropane was studied as a function of time, temperature, and the initial position of the triple bond. At 50°C 9-decyn-1-01, the thermodynamically favoured isomer, was formed rapidly regardless of the initial position of the triple bond. At lower temperatures the appearance of intermediate isomers was observed. The homopropargylic isomer was found to be remarkably stable, and under suitable conditions, conversion of 2-to 3-decyn-1-01 was carried out in 68% isolated yield. SUZANNER. MACAULAY. Can. J. Chem. 58, 2567Chem. 58, (1980. On a etudie I'isom~risation des decynols-1 achaine linkaire en presence d'un sel de sodium du diamino-1,3 propane, en fonction du temps, de la temperature et de la position initiale de la triple liaison. A 50"C, I'isombre thermodynamiquement favorise, le dCcyn-9 01-I, se forme rapidement indkpendamment de la position de la triple liaison. A des tempkratures plus basses on observe la formation d'un isombre intermediaire. On a trouvk que I'isombre homopropargylique est remarquablement stable et dans des conditions convenables la transformation du decyn-2 01-1 en decyn-3 01-1 se fait avec un rendement de 68%.[Traduit par le journal] I

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Exceptionally easy isomerization of acetylenic alcohols with potassium 3-aminopropylamide. A new, high yield synthesis of functionally differentiated αω-difunctional structures

Abstract: Potassium 3-aminopropylamide, readily prepared in situ from K H and 3-aminopropylamine, effects rapid, multipositional isomerization of the triple bond in prop-2-ynylic and other acetylenic alcohols t o the chain terminus remote from the hydroxy function, within minutes at 0-20 "C.

Cited by 46 publications

References 0 publications

Synthetic Studies on the Sporolides: Exploration of the Enediyne Route

Synthetic Studies on the Sporolides: Exploration of the Enediyne Route

Stereospecific Synthesis of (E,Z)- and (Z,Z)-Hexadeca-10,12-dienal. Sex Pheromone Components of Diaphania hyalinata

The rearrangement of isomeric linear decyn-1-ols by reaction with the sodium salt of 1,3-diaminopropane

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