[1423-60-5]  · C4H4O  · 3-Butyn-2-one  · (MW 68.08)

(conjugate acceptor, dienophile)

Physical Data: bp 85 °C; d 0.87 g cm-3.

Solubility: sol chloroform, diethyl ether, ethanol.

Form Supplied in: neat liquid; widely available.

Preparative Methods: from 3-butyn-2-ol using oxidation1,2 or catalytic isomerization.3

Handling, Storage, and Precautions: is a highly toxic, flammable liquid. It is also a severe lachrymator. It may be fatal if inhaled, swallowed, or absorbed through the skin. When handling this material, appropriate protective clothing, safety goggles, and an approved respirator should be worn. The material should be refrigerated when stored. Use in a fume hood.

3-Butyn-2-one has been employed successfully in Pictet-Spengler4 reactions, Diels-Alder and ene reactions,5 1,3-dipolar cycloadditions,6 and cyclotrimerizations.7 A regioisomeric mixture of isoxazoles is produced when 3-butyn-2-one is reacted with bromonitrile oxide (generated in situ).7 The major product is an intermediate in the synthesis of the b-agonist broxaterol.

A variety of nucleophiles successfully add to 3-butyn-2-one (and related alkynones).8,9 Attempts to use 3-butyn-2-one in Robinson annulations have not been very successful.10 Nitro-stabilized carbanions add well using phase transfer catalysis (eq 1), yielding preferentially the (E) isomer.11

Trialkylboranes12 and Tris(trimethylsilyl)aluminum13 efficiently transfer alkyl and trimethylsilyl groups, respectively, in a conjugate fashion.

Asymmetric reduction has been achieved using several different reagents.14-17 Many other alkynones are reduced with high levels of asymmetric induction and the best result to date with 3-butyn-2-one was achieved using either Eapine- or Prapine-Borane.14,18 For more sterically hindered alkynones, (+)-B-Chlorodiisopinocampheylborane works well.14 Reduction of the tosylhydrazone of 3-butyn-2-one produces 1,2-butadiene in reasonable yield.19

Related Reagents.

4-Methoxy-3-buten-2-one; Methyl Vinyl Ketone; Propargyl Aldehyde.

1. Bowden, K.; Heilbron, I. M.; Jones, E. R. H.; Weedon, B. C. L. JCS 1946, 39.
2. Wolf, V. CB 1954, 87, 668.
3. Chabardes, P. TL 1988, 29, 6253.
4. (a) Bailey, P. D.; Hollinshead, S. P.; McLay, N. R.; Everett, J. H.; Reynolds, C. D.; Wood, S. D.; Giordano, F. JCS(P1) 1993, 451. (b) Vercauteren, J.; Lavaud, C.; Lévy, J.; Massiot, G. JOC 1984, 49, 2278.
5. (a) Helmlinger, D.; Fráter, G. HCA 1989, 72, 1515. (b) Giguere, R. J.; Namen, A. M.; Lopez, B. O.; Arepally, A.; Ramos, D. E.; Majetich, G.; Defauw, J. TL 1987, 28, 6553.
6. De Amici, M.; De Micheli, C.; Carrea, G.; Spezia, S. JOC 1989, 54, 2646.
7. Amer, I.; Bernstein, T.; Eisen, M.; Blum, J.; Vollhardt, K. P. C. J. Mol. Catal. 1990, 60, 313.
8. Jung, M. E. COS 1991, 4, 1.
9. Perlmutter, P. Conjugate Addition Reactions in Organic Synthesis; Pergamon: Oxford, 1992; Chapter 7.
10. Woodward, R. B.; Singh, T. JACS 1950, 72, 494.
11. Anderson, D. A.; Hwu, J. R. JOC 1990, 55, 511.
12. Suzuki, A.; Nozawa, S.; Itoh, M.; Brown, H. C.; Kabalka, G. W.; Holland, G. W. JACS 1970, 92, 3503.
13. Altnau, G.; Rosch, L. TL 1983, 24, 45.
14. For a short review of asymmetric reductions of alkynones, see: Ramachandran, P. V.; Teodorović, A. V.; Rangaishenvi, M. V.; Brown, H. C. JOC 1992, 57, 2379.
15. Vigneron, J. P.; Bloy, V. TL 1980, 21, 1735.
16. Midland, M. M.; McDowell, D. C.; Hatch, R. L.; Tramontano, A. JACS 1980, 102, 867.
17. Midland, M. M.; Kazubski, A.; Woodling, R. E. JOC 1991, 56, 1068.
18. Brown, H. C.; Ramachandran, P. V.; Weissman, S. A.; Swaminathan, S. JOC 1990, 55, 6328.
19. Kabalka, G. W.; Newton, Jr., R. J.; Chandler, J. H.; Yang, D. T. C. CC 1978, 726.

Patrick Perlmutter

Monash University, Clayton, Victoria, Australia

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.