1,3-Butadiene Monoxide

[930-22-3]  · C4H6O  · 1,3-Butadiene Monoxide  · (MW 70.09)

(ambident electrophile)

Alternate Names: 3,4-epoxy-1-butene; butadiene epoxide; vinyl epoxide; vinyloxirane.

Physical Data: bp 70 °C; d 0.9006 g cm-3.

Solubility: sol most organic solvents.

Form Supplied in: clear liquid.

Preparative Method: few attempts have been reported to epoxidize conjugated dienes. Recently, a manganese catalyst was employed in a method developed to epoxidize butadiene selectively in one step (eq 1).1

Handling, Storage, and Precautions: the flammable liquid, flash point -50 °C, is a possible carcinogen and should be used in a fume hood.

Nucleophilic Opening at C(1).

Butadiene monoxide is a versatile four-carbon synthon in organic synthesis.2 With the careful choice of reagents one can selectively react nucleophiles at three sites on the carbon backbone. a-Selenobenzyllithiums react at the C(1) position and the resulting intermediates have been transformed into cyclopropanes (eq 2).3 Aminolead reagents displayed even greater selectivity for attack at the C(1) position (eq 3).4

Nucleophilic Opening at C(2).

In Et2O, allylcerium reagents were found to be more regioselective in additions to the 2-position of butadiene monoxide than allyllithium reagents (eq 4).5 In THF the yields and product ratios were comparable. Vinylmagnesium Bromide also adds selectively at the 2-position provided 2-3 equiv of the Grignard reagent are employed (eq 5).6

Nucleophilic Opening at C(4).

The SN2 reaction of organocopper reagents with vinyloxiranes has recently been reviewed.7 A number of SN2 reactions with butadiene monoxide have been facilitated by a palladium catalyst.8 A recent example is found in the synthesis of a linear diene alcohol that was further converted into a cyclopropane-containing eicosanoid of marine origin (eq 6).9 Under standard metalation conditions enol carbamates are readily lithiated, and these acyl anion equivalents also react selectively at the C(4) position without a catalyst (eq 7).10

Functionalization at C(2).

The proton at the 2-position of butadiene monoxide can be selectively deprotonated with t-Butyllithium-N,N,N,N-Tetramethylethylenediamine and silylated with Chlorotrimethylsilane.11 A similar and perhaps more useful reaction involves the reductive metalation of epoxides by various metals.12 Employing Chromium(II) Chloride, the 2-position of butadiene monoxide can be functionalized with reasonable selectivity (eq 8).12a

Related Reagents.

Ethylene Oxide; Isoprene Epoxide; Propylene Oxide.

1. Thomsen, D. S.; Schiott, B.; Jorgensen, K. A. CC 1992, 1072.
2. (a) Larock, R. C. Comprehensive Organic Transformations; VCH: New York, 1989; p 520. (b) Rao, A. S.; Paknikar, S. K.; Kirtane, J. G. T 1983, 39, 2323.
3. (a) Krief, A.; Hobe, M. SL 1992, 317. (b) Williams, K.; Thompson, C. M. SC 1992, 22, 239. (c) Oppolzer, W.; Gaudin, J.-M.; Bedoya-Zurita, M.; Hueso-Rodriguez, J.; Raynham, T. M.; Robyr, C. TL 1988, 29, 4709.
4. Yamada, J.; Yumoto, M.; Yamamoto, Y. TL 1989, 30, 4255.
5. Fukuzawa, S.; Sakai, S. BCJ 1992, 65, 3308.
6. Yamaguchi, R., Hamasaki, T.; Sasaki, T.; Ohta, T.; Utimoto, K.; Kozima, S.; Takaya, H. JOC 1993, 58, 1136.
7. Marshall, J. A. CRV 1989, 89, 1503.
8. (a) Larock, R. C.; Ding, S. JOC 1993, 58, 804. (b) Sutowardoyo, K. I.; Emziane, M.; Lhoste, P.; Sinou, D. T 1991, 47, 1435. (c) Safi, M.; Sinou, D. TL 1991, 32, 2025. (d) Tueting, D. R.; Echavarren, A. M.; Stille, J. K. T 1989, 45, 979. (e) Trost, B. M.; Lee, D. C. JOC 1989, 54, 2271.
9. White, J. D.; Jensen, M. S. JACS 1993, 115, 2970.
10. Sengupta, S.; Snieckus, V. J. JOC 1990, 55, 5680.
11. Eisch, J. J.; Galle, J. E. JOC 1990, 55, 4835.
12. (a) Fujimura, O.; Takai, K.; Utimoto, K. JOC 1990, 55, 1705. (b) Cohen, T.; Jeong, I-H.; Mudryk, B.; Bhupathy, M.; Awad, M. M. A. JOC 1990, 55, 1528.

Edward W. Thomas

The Upjohn Company, Kalamazoo, MI, USA

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