Categories: Synthesis of O-Heterocycles, C-O Bond Formation, Synthesis of cyclic ethers >
Synthesis of tetrahydropyrans
Recent Literature
The platinum-catalyzed hydroalkoxylation of γ- and δ-hydroxy olefins
tolerated various substitution patterns and a number of functional groups
including pivaloate and acetate esters, amides, silyl and benzyl ethers, and
pendant hydroxyl and olefinic groups.
H. Qian, X. Han, R. A. Widenhoefer, J. Am. Chem. Soc.,
2004, 126, 9536-9537.
H. Qian, X. Han, R. A. Widenhoefer, J. Am. Chem. Soc.,
2004, 126, 9536-9537.
The reaction of tertiary 1,4- and 1,5-diols with cerium ammonium nitrate at room
temperature gives tetrahydrofuran and tetrahydropyran derivatives in high yield
and stereoselectivity. Various fragrant compounds have been synthesized using
this method.
E. J. Alvarez-Manzaneda, R. Chabouna, E. Alvarez, E. Cabrera, R.
Alvarez-Manzaneda, A. Haidour, J. M. Ramos, Synlett, 2006,
1756-1758.
Silver(I) triflate catalyzes intramolecular additions of hydroxyl or carboxyl groups to olefins
in good to excellent yields for a range of substrates under relatively mild conditions. This
reaction is one of the simplest methods to construct cyclic ethers or
lactones.
C.-G. Yang, N. W. Reich, Z. Shi, C. He, Org. Lett.,
2005, 7, 4553-4556.
The Au(I)-catalyzed intramolecular hydroamination of N-allenyl
carbamates was effective for the formation of various cyclic amines. γ-Hydroxy
and δ-hydroxy allenes underwent Au-catalyzed intramolecular
hydroalkoxylation to form the corresponding
oxygen heterocycles in good yield. 2-Allenyl indoles
underwent Au-catalyzed intramolecular hydroarylation to form 4-vinyl tetrahydrocarbazoles in good yield.
Z. Zhang, C. Liu, R. E. Kinder, X. Han, H. Qian, R. A. Widenhoefer, J. Am. Chem. Soc.,
2006, 128, 9066-9073.
2-(Arylmethylene)cyclopropylcarbinols could be converted to the corresponding
tetrahydropyrans stereoselectively in the presence of Brønsted acids under mild
conditions. A plausible Prins-type reaction mechanism has been proposed.
G.-Q. Tian, M. Shi, Org. Lett., 2007,
9, 2405-2408.
Cyclization of δ-halocarbanions to cyclobutanes is a relatively slow process,
thus formation of tetrahydropyran derivatives via addition to aldehydes and
subsequent cyclization is possible in high yield. A simple mechanistic
discussion, optimization of the reaction conditions, and the scope of the
reaction are discussed.
M. Barbasiewicz, A. Brud, M. Mąkosza, Synthesis, 2007,
1209-1213.
Phosphomolybdic acid catalyzes efficiently the Prins cyclization of homoallylic
alcohols with aldehydes in water at room temperature to provide
tetrahydropyran-4-ol derivatives in high yields with all cis-selectivity.
The use of phosphomolybdic acid in water makes this procedure simple, convenient,
cost-effective, and environmentally friendly.
J. S. Yadav, B. V. S. Reddy, G. G. K. S. N. Kumar, S. Aravind, Synthesis, 2008,
395-400.
1-n-Butyl-3-methylimidazolium chloroaluminate [bmin]Cl .
AlCl3
was successfully employed as a reaction medium for Prins cyclizations, to
produce 4-chlorotetrahydropyran derivatives in short reaction times.
J. S. Yadav, B. V. S. Reddy, M. S. Reddy, N.
Niranjan, A. R. Prasad, Eur. J. Org. Chem., 2003, 1779-1783.
Aldehydes undergo rapid and selective coupling with 3-buten-1-ol in the
presence of 20 mol% of niobium(V) chloride to afford 4-chlorotetrahydropyran
derivatives under extremely mild conditions in excellent yields. Similar
halogenated tetrahydropyrans are also obtained using gallium(III) halides.
J. S. Yadav, B. V. Subba Reddy, M. K. Gupta, S. K. Biswas, Synthesis,
2004, 2711-2715.
An efficient method allows the construction of 2,6-cis-4,5-dibromo-tetrasubstituted
tetrahydropyran rings with well-controlled stereochemistry in good yields.
F. Liu, T.-P. Loh, Org. Lett., 2007,
9, 2063-2066.
F. Liu, T.-P. Loh, Org. Lett., 2007,
9, 2063-2066.
A highly stereoselective route to 2,4,5-trisubstituted tetrahydropyrans
employs an intramolecular allylation of a (Z)-allylsilane onto an
aldehyde under Brønsted acid activation.
P. J. Jervis, B. M. Kariuki, L. R. Cox, Org. Lett.,
2006, 8, 4637-4640.
A new convergent synthetic approach to the 2-hydroxypyran motif common to many
naturally occurring structures includes the esterification of two fragments and
a subsequent intramolecular reductive cyclization.
L. V. Heumann, G. E. Keck, Org. Lett., 2007,
9, 1951-1954.
An intramolecular iodo-aldol cyclization of prochiral α-substituted enoate
aldehydes and ketones produces hetero- and carbocycles containing quaternary centers adjacent
to secondary or tertiary centers. The reactions occur in good yields and are
highly trans-selective with hydroxyl and iodomethyl
groups on opposite faces of the ring system.
F. Douelle, A. S. Capes, M. F. Greaney, Org. Lett., 2007,
9, 1931-1934.
A comparative study of chiral Mo- and Ru-based catalysts to promote
enantioselective synthesis of 2,6-disubstituted pyrans and piperidines through
asymmetric ring-opening/cross-metathesis reactions demonstrated the critical
complementarity that exists between the two classes of chiral catalysts.
G. A. Cortez, C. A. Baxter, R. R. Schrock, A. H. Hoveyda, Org. Lett., 2007,
9, 2871-2874.
Treatment of 3-[(alkoxycarbonyl)alkyl]-substituted conjugated cycloalkenones
with diisobutylaluminum hydride at -78 °C followed by acid quenching
furnishes spiro ethers, whereas the corresponding 3-(carboxyalkyl)-substituted
cycloalkenones generate spiro lactones upon reaction with sodium borohydride
at 30 °C followed by acid quenching.
M.-C. P. Yeh, Y.-C. Lee, T.-C. Young, Synthesis, 2006, 3621-3624.
The first enantioselective intramolecular catalytic Stetter reaction, which
opens up a short and efficient pathway to enantiomerically enriched
chroman-4-ones, is reported.
D. Enders, K. Breuer, J. Runsink, Helv. Chim. Acta, 1996, 79, 1899-1902.
An efficient and regioselective Yb(OTf)3-promoted
palladium-catalyzed oxidative cyclization of γ-heteroalkenyl β-keto amides
has been developed. Under simple aerobic condition, various six-, seven-,
and eight-membered-ring N- and O-heterocycles were obtained in excellent yield.
K.-T. Yip, J.-H. Li, O.-Y. Lee, D. Yang, Org. Lett.,
2005, 7, 5717-5719.
A direct Pd-catalyzed arylation reaction for the intramolecular formation of
biaryl compounds using a novel phosphine ligand offers enhanced catalytic
activity for transformations of previously unreactive substrates.
L.-C. Campeau, M. Parisien, M. Leblanc, K. Fagnou, J. Am. Chem. Soc.,
2004, 126, 9186-9187.
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Diastereoselective and Enantioselective Construction of Cyclic Ethers Stereocontrolled Construction of Cyclic Ethers Enantioselective Construction of Naturally-Occurring Cyclic Ethers |
