Wikipedia

2-Methylbut-3-yn-2-ol

2-Methylbut-3-yn-2-ol is the organic compound with the formula HC2C(OH)Me2 (Me = CH3). A colorless liquid, it is classified as an alkynyl alcohol.

2-Methylbut-3-yn-2-ol
Names
Preferred IUPAC name
2-Methylbut-3-yn-2-ol
Other names
  • Ethynylmethylcarbinol
  • Dimethylethynylcarbinol
  • 1,1-Dimethyl-2-propyn-1-ol
  • Dimethylethynylmethanol
  • MB
  • Mebynol
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.003.700 Edit this at Wikidata
EC Number
  • 204-070-5
RTECS number
  • ES0810000
UNII
UN number 1987
  • InChI=1S/C5H8O/c1-4-5(2,3)6/h1,6H,2-3H3
    Key: CEBKHWWANWSNTI-UHFFFAOYSA-N
  • CC(C)(C#C)O
Properties
C5H8O
Molar mass 84.118 g·mol−1
Appearance Colorless liquid
Density 0.8637 g/cm3
Melting point 3 °C (37 °F; 276 K)
Boiling point 104 °C (219 °F; 377 K)
good
Hazards
GHS labelling:
GHS02: FlammableGHS05: CorrosiveGHS07: Exclamation markGHS08: Health hazard
Danger
H225, H226, H302, H315, H318, H319, H335, H361
P201, P202, P210, P233, P240, P241, P242, P243, P261, P264, P270, P271, P280, P281, P301 P312, P302 P352, P303 P361 P353, P304 P340, P305 P351 P338, P308 P313, P310, P312, P321, P330, P332 P313, P337 P313, P362, P370 P378, P403 P233, P403 P235, P405, P501
Flash point 20 °C (68 °F; 293 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Preparation and use

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It arises from the condensation of acetylene and acetone. The addition can be promoted with base[1] (Favorskii reaction) or with Lewis acid catalysts.[2] 2-Methylbut-3-yn-2-ol is produced on an industrial scale as a precursor to terpenes and terpenoids.

 
2-Methylbut-3-yn-2-ol is an intermediate in this industrial route to geraniol.[3]

2-Methylbut-3-yn-2-ol also is used as a monoprotected version of acetylene. For example, after arylation at carbon, the acetone can be removed with base:[4]

HC2C(OH)Me2 ArX base → ArC2C(OH)Me2 [Hbase]X
ArC2C(OH)Me2 → ArC2H OCMe2

In this regard, 2-methylbut-3-yn-2-ol is used similarly to trimethylsilylacetylene.

References

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  1. ^ Donald D. Coffman (1940). "Dimethylethynylcarbinol". Org. Synth. 20: 40. doi:10.15227/orgsyn.020.0040.
  2. ^ Frantz, Doug E.; Fässler, Roger; Carreira, Erick M. (2000). "Facile Enantioselective Synthesis of Propargylic Alcohols by Direct Addition of Terminal Alkynes to Aldehydes". J. Am. Chem. Soc. 122 (8): 1806–1807. doi:10.1021/ja993838z.1806-1807&rft.date=2000&rft_id=info:doi/10.1021/ja993838z&rft.aulast=Frantz&rft.aufirst=Doug E.&rft.au=Fässler, Roger&rft.au=Carreira, Erick M.&rfr_id=info:sid/en.wikipedia.org:2-Methylbut-3-yn-2-ol" class="Z3988">
  3. ^ Eberhard Breitmaier (2006). Terpenes: Flavors, Fragrances, Pharmaca, Pheromones. Wiley-VCH. doi:10.1002/9783527609949. ISBN 9783527609949.
  4. ^ Gordon, John (2001). "2-Methylbut-3-yn-2-ol". e-EROS Encyclopedia of Reagents for Organic Synthesis. pp. 1–2. doi:10.1002/047084289X.rm157. ISBN 0471936235.1-2&rft.date=2001&rft_id=info:doi/10.1002/047084289X.rm157&rft.isbn=0471936235&rft.au=Gordon, John&rfr_id=info:sid/en.wikipedia.org:2-Methylbut-3-yn-2-ol" class="Z3988">
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