oxetane

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

| author =C. R. Noller

| year =1955

| title =Trimethylene Oxide

| volume =29

| pages =92

| collvol =3

| collvolpages =835

| prep =CV3P0835}}

File:Synthesis of trimethylene oxide.png

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{{sfn|Patai|1967|pp=411-413}} as well as through decarboxylation of a six-membered cyclic carbonate.{{cn|date=March 2024}}

More than a hundred different oxetanes have been synthesized.{{cn|date=September 2024}} Functional groups can be added into any desired position in the oxetane ring, including fully fluorinated (perfluorinated) and fully deuterated analogues. Major examples are:

Image:Taxol.svg 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.{{cite journal |last1=Willenbring |first1=Dan |last2=Tantillo |first2=Dean J. |title=Mechanistic possibilities for oxetane formation in the biosynthesis of Taxol's D ring |journal=Russian Journal of General Chemistry |date=April 2008 |volume=78 |issue=4 |pages=723–731 |doi=10.1134/S1070363208040336 |s2cid=98056619 }} 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.

Oxetanes are less reactive than epoxides, and generally unreactive in basic conditions,{{sfn|Patai|1967|p=425}} although Grignard reagents at elevated temperatures{{sfn|Patai|1967|pp=63,425}} and complex hydrides will cleave them.{{sfn|Patai|1967|pp=67-68}} However, the ring strain does make them much more reactive than larger rings,{{sfn|Patai|1967|pp=376-377}} and oxetanes decompose in the presence of even mildly acidic nucleophiles.{{cite book|title=The Chemistry of the Ether Linkage|editor-first=Saul|editor-last=Patai|year=1967|series=The Chemistry of Functional Groups|publisher=Interscience / William Clowes and Sons|location=London|lccn=66-30401|pages=28–30}} In non-nucleophilic acids, they mainly isomerize to allyl alcohols.{{sfn|Patai|1967|p=696}}

Noble metals tend to catalyze isomerization to a carbonyl.{{sfn|Patai|1967|pp=697,700}}

In industry, the parent compound, oxetane polymerizes to polyoxetane in the presence of a dry acid catalyst,Penczek & Penczek (1963), "Kinetics and mechanism of heterogeneous polymerization of 3,3-bis(chloromethyl)oxetane catalyzed by gaseous BF₃" in Die Makromolekuläre Chemie. Wiley. although the compound was described in 1967 as "rarely polymerized commercially".{{sfn|Patai|1967|p=380}}

• β-Propiolactone or 2-oxetanone.
• 3-Oxetanone

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