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One classic procedure for the [[organic synthesis]] of tetrahydropyran is by [[hydrogenation]] of the 3,4-[[isomer]] of [[dihydropyran]] with [[Raney nickel]].<ref>{{OrgSynth | title = Tetrahydropyran | first1 = D. W. | last1 = Andrus | first2 = John R. | last2 = Johnson | collvol = 3 | collvolpages = 794 | year = 1943 | volume = 23 | pages = 90 | prep = cv3p0794 | doi = 10.15227/orgsyn.023.0090}}</ref>
One classic procedure for the [[organic synthesis]] of tetrahydropyran is by [[hydrogenation]] of the 3,4-[[isomer]] of [[dihydropyran]] with [[Raney nickel]].<ref>{{OrgSynth | title = Tetrahydropyran | first1 = D. W. | last1 = Andrus | first2 = John R. | last2 = Johnson | collvol = 3 | collvolpages = 794 | year = 1943 | volume = 23 | pages = 90 | prep = cv3p0794 | doi = 10.15227/orgsyn.023.0090}}</ref>


==Tetrahydropyranyl derivatives==
==Reactions==
In [[organic synthesis]], the 2-tetrahydropyranyl group is used as a [[protecting group]] for [[alcohol]]s.<ref>{{OrgSynth | title = Methyl 4-Hydroxy-2-butynoate | first1 = R. A. | last1 = Earl | first2 = L. B. | last2 = Townsend | collvol = 7 | collvolpages = 334 | year = 1981 | volume = 60 | page = 81 | doi = 10.15227/orgsyn.060.0081 | prep = cv7p0334}}</ref><ref>{{OrgSynth | title =<nowiki>Diethyl [(2-Tetrahydropyranyloxy)methyl]phosphonate</nowiki> | first = Arthur F. | last = Kluge | collvol = 7 | collvolpages = 160 | year = 1986 | volume = 64 | page = 80 | doi = 10.15227/orgsyn.064.0080 | prep = cv7p0160}}</ref> Reaction of the alcohol with [[3,4-dihydropyran]] forms a 2-tetrahydropyranyl ether, protecting the alcohol from a variety of reactions. The alcohol can later be restored readily by acidic [[hydrolysis]] with formation of 5-hydroxypentanal.<ref name = Greene />
Although tetrahydropyran is an obscure organic compound]], tetrahydropyranyl ethers are of broad utility in [[organic synthesis]]. Specifically, the 2-tetrahydropyranyl (THP) group is a common [[protecting group]] for [[alcohol]]s.<ref>{{OrgSynth | title = Methyl 4-Hydroxy-2-butynoate | first1 = R. A. | last1 = Earl | first2 = L. B. | last2 = Townsend | collvol = 7 | collvolpages = 334 | year = 1981 | volume = 60 | page = 81 | doi = 10.15227/orgsyn.060.0081 | prep = cv7p0334}}</ref><ref>{{OrgSynth | title =<nowiki>Diethyl [(2-Tetrahydropyranyloxy)methyl]phosphonate</nowiki> | first = Arthur F. | last = Kluge | collvol = 7 | collvolpages = 160 | year = 1986 | volume = 64 | page = 80 | doi = 10.15227/orgsyn.064.0080 | prep = cv7p0160}}</ref> Alcohols react with with [[3,4-Dihydropyran|3,4-dihydropyran]] to give 2-tetrahydropyranyl ethers. These ethers are resilient to a variety of reactions. The alcohol can later be restored by acid-catalyzed [[hydrolysis]]. This hydrolysis reforms the parent alcohol as well as 5-hydroxypentanal.<ref name = Greene />


:[[File:THP ether.png|450px|THP protective groups]]
:[[File:THP ether.png|450px|THP protective groups]]

Revision as of 04:21, 16 January 2019

This article is about tetrahydropyran, whose IUPAC name is oxane. For ethylene oxide, which has occasionally been named as oxane, see oxirane.
Tetrahydropyran
Tetrahydropyran
Tetrahydropyran
THP
THP
Names
IUPAC name
Oxane
Other names
Tetrahydropyran,
Oxacyclohexane
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
DrugBank
ECHA InfoCard 100.005.048 Edit this at Wikidata
KEGG
UNII
  • InChI=1S/C5H10O/c1-2-4-6-5-3-1/h1-5H2 checkY
    Key: DHXVGJBLRPWPCS-UHFFFAOYSA-N checkY
  • InChI=1/C5H10O/c1-2-4-6-5-3-1/h1-5H2
    Key: DHXVGJBLRPWPCS-UHFFFAOYAV
  • O1CCCCC1
Properties
C5H10O
Molar mass 86.134 g·mol−1
Density 0.880 g/cm3
Melting point −45 °C (−49 °F; 228 K)
Boiling point 88 °C (190 °F; 361 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Tetrahydropyran (THP) is the organic compound consisting of a saturated six-membered ring containing five carbon atoms and one oxygen atom. It is named by reference to pyran, which contains two double bonds, and may be produced from it by adding four hydrogens. In 2013, its preferred IUPAC name was established as oxane.[1] The compound is a colourless volatile liquid, but is obscure. Derivatives of tetrahydropyran are, however, more common. 2-Tetrahydropyranyl (THP-) ethers derived from the reaction of alcohols and 3,4-dihydropyran are commonly used as protecting groups in organic synthesis.[2] Furthermore, a tetrahydropyran ring system, i.e., five carbon atoms and an oxygen, is the core of pyranose sugars, such as glucose. In gas phase, the THP exists in its lowest energy Cs symmetry chair conformation.[3]

Preparation

One classic procedure for the organic synthesis of tetrahydropyran is by hydrogenation of the 3,4-isomer of dihydropyran with Raney nickel.[4]

Tetrahydropyranyl derivatives

Although tetrahydropyran is an obscure organic compound]], tetrahydropyranyl ethers are of broad utility in organic synthesis. Specifically, the 2-tetrahydropyranyl (THP) group is a common protecting group for alcohols.[5][6] Alcohols react with with 3,4-dihydropyran to give 2-tetrahydropyranyl ethers. These ethers are resilient to a variety of reactions. The alcohol can later be restored by acid-catalyzed hydrolysis. This hydrolysis reforms the parent alcohol as well as 5-hydroxypentanal.[2]

THP protective groups

Alcohol protection

In organic synthesis, 2-tetrahydropyranyl group (THP) is used as a protecting group for alcohols by the formation of THP ethers.

Most common protection methods

THP protection used in the total synthesis of solandelactone E[7]

Most common deprotection methods

See also

  • Pyran
  • Dioxane and Trioxane, which have two and three oxygen atoms as part of their six-membered rings respectively

References

  1. ^ "New IUPAC Organic Nomenclature - Chemical Information BULLETIN" (PDF).
  2. ^ a b c Wuts, Peter G. M.; Greene, Theodora W. (2006). "Protection for the Hydroxyl Group, Including 1,2‐ and 1,3‐Diols". Greene's Protective Groups in Organic Synthesis (4th ed.). pp. 16–366. doi:10.1002/9780470053485.ch2. ISBN 9780470053485.
  3. ^ Builth-Williams, J. D.; Bellm, S. M.; Chiari, L.; Thorn, P. A.; Jones, D. B.; Chaluvadi, H.; Madison, D. H.; Ning, C. G.; Lohmann, B. (2013). "A dynamical (e,2e) investigation of the structurally related cyclic ethers tetrahydrofuran, tetrahydropyran, and 1,4-dioxane" (PDF). Journal of Chemical Physics. 139 (3): 034306. doi:10.1063/1.4813237.
  4. ^ Andrus, D. W.; Johnson, John R. (1943). "Tetrahydropyran". Organic Syntheses. 23: 90. doi:10.15227/orgsyn.023.0090; Collected Volumes, vol. 3, p. 794.
  5. ^ Earl, R. A.; Townsend, L. B. (1981). "Methyl 4-Hydroxy-2-butynoate". Organic Syntheses. 60: 81. doi:10.15227/orgsyn.060.0081; Collected Volumes, vol. 7, p. 334.
  6. ^ Kluge, Arthur F. (1986). "Diethyl [(2-Tetrahydropyranyloxy)methyl]phosphonate". Organic Syntheses. 64: 80. doi:10.15227/orgsyn.064.0080; Collected Volumes, vol. 7, p. 160.
  7. ^ Robinson, Anna; Aggarwal, Varinder K. (2010). "Asymmetric Total Synthesis of Solandelactone E: Stereocontrolled Synthesis of the 2-ene-1,4-diol Core through a Lithiation–Borylation–Allylation Sequence". Angewandte Chemie International Edition. 49 (37): 6673–6675. doi:10.1002/anie.201003236.
source: https://en.wikipedia.org/w/index.php?title=Tetrahydropyran&diff=prev&oldid=878654006

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