Oxetane, or 1,3-propylene oxide, is a heterocyclic organic compound with the molecular formula C
3
H
6
O
, having a four-membered ring with three carbon atoms and one oxygen atom.

Oxetane
Names
Preferred IUPAC name
Oxetane[1]
Systematic IUPAC name
1,3-Epoxypropane
Oxacyclobutane
Other names
1,3-Propylene oxide
Trimethylene oxide
Identifiers
3D model (JSmol)
102382
ChEBI
ChemSpider
ECHA InfoCard 100.007.241 Edit this at Wikidata
EC Number
  • 207-964-3
239520
UNII
UN number 1280
  • InChI=1S/C3H6O/c1-2-4-3-1/h1-3H2 checkY
    Key: AHHWIHXENZJRFG-UHFFFAOYSA-N checkY
  • InChI=1/C3H6O/c1-2-4-3-1/h1-3H2
    Key: AHHWIHXENZJRFG-UHFFFAOYAE
  • C1CCO1
Properties
C3H6O
Molar mass 58.08 g/mol
Density 0.8930 g/cm3
Melting point −97 °C (−143 °F; 176 K)
Boiling point 49 to 50 °C (120 to 122 °F; 322 to 323 K)
1.3895 at 25 °C
Hazards
GHS labelling:
GHS02: FlammableGHS07: Exclamation mark
Danger
H225, H302, H312, H332
P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P301+P312, P302+P352, P303+P361+P353, P304+P312, P304+P340, P312, P322, P330, P363, P370+P378, P403+P235, P501
Flash point −28.3 °C; −19.0 °F; 244.8 K (NTP, 1992)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)

The term "an oxetane" or "oxetanes" refer to any organic compound containing the oxetane ring.

Production

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A typical well-known method of preparation is the reaction of potassium hydroxide with 3-chloropropyl acetate at 150 °C:[2]

 

Yield of oxetane made this way is c. 40%, as the synthesis can lead to a variety of by-products including water, potassium chloride, and potassium acetate.

Another possible reaction to form an oxetane ring is the Paternò–Büchi reaction. The oxetane ring can also be formed through diol cyclization[3] as well as through decarboxylation of a six-membered cyclic carbonate.[citation needed]

Derivatives

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More than a hundred different oxetanes have been synthesized.[citation needed] Functional groups can be added into any desired position in the oxetane ring, including fully fluorinated (perfluorinated) and fully deuterated analogues. Major examples are:

Name Structure Boiling point, Bp [°C]
3,3-Bis(chloromethyl)oxetane   198[4]
3,3-Bis(azidomethyl)oxetane   165[5]
2-Methyloxetane   60[citation needed]
3-Methyloxetane   67[citation needed]
3-Azidooxetane   122[6]
3-Nitrooxetane   195[7]
3,3-Dimethyloxetane   80[citation needed]
3,3-Dinitrooxetane  

Taxol

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Paclitaxel with oxetane ring at right.

Paclitaxel (Taxol) is an example of a natural product containing an oxetane ring. Taxol has become a major point of interest among researchers due to its unusual structure and success in the involvement of cancer treatment.[8] The attached oxetane ring is an important feature that is used for the binding of microtubules in structure activity; however little is known about how the reaction is catalyzed in nature, which creates a challenge for scientists trying to synthesize the product.[8]

Reactions

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Oxetanes are less reactive than epoxides, and generally unreactive in basic conditions,[9] although Grignard reagents at elevated temperatures[10] and complex hydrides will cleave them.[11] However, the ring strain does make them much more reactive than larger rings,[12] and oxetanes decompose in the presence of even mildly acidic nucleophiles.[13] In non-nucleophilic acids, they mainly isomerize to allyl alcohols.[14]

Noble metals tend to catalyze isomerization to a carbonyl.[15]

In industry, the parent compound, oxetane polymerizes to polyoxetane in the presence of a dry acid catalyst,[16] although the compound was described in 1967 as "rarely polymerized commercially".[17]

See also

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References

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  1. ^ Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. p. 147. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4.
  2. ^ C. R. Noller (1955). "Trimethylene Oxide". Organic Syntheses. 29: 92; Collected Volumes, vol. 3, p. 835.
  3. ^ Patai 1967, pp. 411–413.
  4. ^ "78-71-7 CAS MSDS (3,3-BIS(CHLOROMETHYL)OXETANE) Melting Point Boiling Point Density CAS Chemical Properties". www.chemicalbook.com. Retrieved 2022-12-28.
  5. ^ Akhtar, Tauseef; Berger, Ronald; Marine, Joseph E; Daimee, Usama A; Calkins, Hugh; Spragg, David (2020-08-13). "Cryoballoon Ablation of Atrial Fibrillation in Octogenarians". Arrhythmia & Electrophysiology Review. 9 (2): 104–107. doi:10.15420/aer.2020.18. ISSN 2050-3377. PMC 7491081. PMID 32983532.
  6. ^ Baum, Kurt; Berkowitz, Phillip T.; Grakauskas, Vytautas; Archibald, Thomas G. (September 1983). "Synthesis of electron-deficient oxetanes. 3-Azidooxetane, 3-nitrooxetane, and 3,3-dinitrooxetane". The Journal of Organic Chemistry. 48 (18): 2953–2956. doi:10.1021/jo00166a003. ISSN 0022-3263.
  7. ^ "3-Nitrooxetane | C3H5NO3 | ChemSpider". www.chemspider.com. Retrieved 2022-12-28.
  8. ^ a b Willenbring, Dan; Tantillo, Dean J. (April 2008). "Mechanistic possibilities for oxetane formation in the biosynthesis of Taxol's D ring". Russian Journal of General Chemistry. 78 (4): 723–731. doi:10.1134/S1070363208040336. S2CID 98056619.
  9. ^ Patai 1967, p. 425.
  10. ^ Patai 1967, pp. 63, 425.
  11. ^ Patai 1967, pp. 67–68.
  12. ^ Patai 1967, pp. 376–377.
  13. ^ Patai, Saul, ed. (1967). The Chemistry of the Ether Linkage. The Chemistry of Functional Groups. London: Interscience / William Clowes and Sons. pp. 28–30. LCCN 66-30401.
  14. ^ Patai 1967, p. 696.
  15. ^ Patai 1967, pp. 697, 700.
  16. ^ Penczek & Penczek (1963), "Kinetics and mechanism of heterogeneous polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by gaseous BF3" in Die Makromolekuläre Chemie. Wiley.
  17. ^ Patai 1967, p. 380.