1123-11-1Relevant articles and documents
A three-carbon (n+1+2) ring expansion method for the synthesis of macrocyclic enones. Application to muscone synthesis
Erden, Ihsan,Cao, Weiguo,Price, Mary,Colton, Michael
, p. 5497 - 5501 (2008)
The three-carbon ring expansion methodology commences with the preparation of a cyclic allene (C9, C11, C13), readily available from the corresponding cycloalkene via dibromocarbene addition and subsequent treatment with methyllithium. Dichloroketene addition to the cyclic allene regioselectively provides the [2+2] cycloadduct, which is reductively dechlorinated with zinc in methanol. The resulting cyclobutanone is then catalytically hydrogenated; cyclobutanone ring opening is affected with trimethylsilyl iodide; immediate dehydroiodination of the resulting β-iodocycloalkanone with diazabicycloundecane (DBU) provides the corresponding macrocyclic enone. The 15-membered enone was converted to d,l-muscone with (CH3)2CuLi.
Sydnes,Skattebol
, p. 3703,3704 (1974)
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Nozaki,H. et al.
, p. 905 - 913 (1971)
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Reeves,Stroebel
, p. 2945 (1971)
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Seyferth,D.,Lambert,R.L.
, p. 31 - 45 (1975)
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Hargrove,R.J.,Stang,P.J.
, p. 37 - 41 (1976)
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Palladium- and Rhodium-Catalyzed Dynamic Kinetic Resolution of Racemic Internal Allenes Towards Chiral Pyrazoles
Hilpert, Lukas J.,Sieger, Simon V.,Haydl, Alexander M.,Breit, Bernhard
supporting information, p. 3378 - 3381 (2019/02/06)
A complementing Pd- and Rh-catalyzed dynamic kinetic resolution (DKR) of racemic allenes leading to N-allylated pyrazoles is described. Such compounds are of enormous interest in medicinal chemistry as certified drugs and potential drug candidates. The new methods feature high chemo-, regio- and enantioselectivities aside from displaying a broad substrate scope and functional group compatibility. A mechanistic rational accounting for allene racemization and trans-alkene selectivity is discussed.
Regioselective radical bromoallylation of allenes leading to 2-bromo-substituted 1,5-dienes
Kippo, Takashi,Fukuyama, Takahide,Ryu, Ilhyong
supporting information; experimental part, p. 3864 - 3867 (2011/09/15)
The regioselective radical bromoallylation of allenes proceeded efficiently in the presence of AIBN as a radical initiator to give 2-bromo-substituted 1,5-dienes in excellent yields. The addition of a bromine radical took place regioselectively onto the central carbon of allenes generating a stable allyl radical, which underwent addition/β-fragmentation reactions with allylbromides. The products could be further functionalized by Pd-catalyzed coupling reactions.