Categories: C-C Bond Formation > Carbocyclic compounds > Cyclic ketones
Synthesis of cycloheptanones and higher homologues
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Recent Literature
Functionalized α-tertiary and -quaternary 2-arylcycloalkanones are rapidly
accessed by scandium(III) triflate-catalyzed diazoalkane-carbonyl homologations.
Pairing readily available bis- and tris(oxazoline) based ligands with scandium
triflate allows access to arylated medium ring carbocycles with high
enantioselectivities and excellent yield.
V. L. Rendina, H. Z. Kaplan, J. S. Kingsbury, Synthesis, 2012, 44,
686-693.
V. L. Rendina, H. Z. Kaplan, J. S. Kingsbury, Synthesis, 2012, 44,
686-693.
A highly diastereoselective insertion of α-alkyldiazoacetates to cyclohexanone
and its heteroanalogues furnishes seven-membered rings with
1,4-quaternary-tertiary, 1,4-quaternary-quaternary, or
1,3,5-quaternary-tertiary-tertiary stereogenic centers in a single operation
starting from readily available materials.
T. Hashimoto, Y. Naganawa, K. Maruoka, J. Am. Chem. Soc., 2009,
131, 6614-6617.
Treatment of 1,6-dialkylhexa-1,5-diene-3,4-diones with bis(iodozincio)methane
gave zinc alkoxides of cis-5,6-dialkylcyclohepta-3,7-diene-1,3-diol in
good yields at room temperature via a cis-divinylcyclopropane-1,2-diol
and a subsequent Cope rearrangement. The reaction proceeded with high
stereospecificity.
Y. Takada, K. Nomura, S. Matubara, Org. Lett., 2010,
12, 5204-5205.
Metal-catalyzed, regioselective [5 + 2] cycloadditions of vinylcyclopropanes and
electron-rich alkynes (ynol ethers) provide dioxygenated seven-membered rings, a
common feature of numerous natural and non-natural targets and building blocks
for synthesis. The reactions proceed in high yield at room temperature and
tolerate a broad range of functionalities.
P. A. Wender, C. Ebner, B. D. Fennell, F. Inagaki, B. Schröder, Org. Lett.,
2017, 19, 5810-5813.
Rh-catalyzed [5 + 2] cycloadditions of 1-(2-methyoxyethoxy)-1-vinylcyclopropane
as a five-carbon component to alkynes provide cycloheptenones in many cases in
minutes and in very good isolated yields. The procedure is readily conducted on
a small or large scale.
P. A. Wender, A. J. Dyckman, C. O. Husfeld, M. J. C. Scanio,
Org. Lett., 2000, 2, 1609-1611.
A [6 + 2] annulation that involves the combination of β-alkenoyl acylsilanes
and a vinyllithium derivative enables in one operation and a stereoselective
manner the construction of eight-membered ring systems containing useful
functionalities for further synthetic elaboration from readily available six-
and two-carbon components.
K. Takeda, H. Haraguchi, Y. Okamoto, Org. Lett.,
2003, 5, 3705-3707.
The reaction of β-keto esters with CF3CO2ZnCH2I
provided the corresponding chain-extended products in moderate to good
yields. α-Substituted acyclic β-keto esters reacted less efficiently than
cyclic β-keto esters or simple β-keto esters.
S. Xue, Y.-K. Liu, L.-Z. Li, Q.-X. Guo, J. Org. Chem., 2005,
70, 8245-8247.
[ReBr(CO)3(thf)]2 catalyzes the reaction of a
1,3-dicarbonyl cyclic compound with an acetylene to give a medium-sized cyclic
compound in excellent yield. By using isocyanide as an additive, the insertion
of acetylenes into a carbon-carbon single bond occurs under mild conditions.
Y. Kuninobu, A. Kawata, K. Takai, J. Am. Chem. Soc., 2006, 128,
11368-11369.