[764-41-0]  · C4H6Cl2  · 1,4-Dichloro-2-butene  · (MW 125.00) (cis)

[1476-11-5] (trans)


(a versatile four-carbon synthon useful in cycloalkylations1-7 and cycloadditions11-14; forms heterocyclic systems in reactions with heteroatom nucleophiles15-18)

Physical Data: cis (95%): mp 48 °C; bp 152 °C; d 1.188 g cm-3. trans (98%): bp 74-76 °C/40 mmHg; d 1.183 g cm-3. cis/trans (95%): bp 72-75 °C/40 mmHg; d 1.183 g cm-3.

Solubility: sol most organic solvents.

Form Supplied in: available as neat liquid as pure cis or trans forms and a cis/trans mixture.

Handling, Storage, and Precautions: flammable liquid; lachrymator, irritant, and corrosive, handle in a fume hood.

Carbocycles via Dianion Alkylations.

gem-Dianions generated from active methylene compounds react with trans-1,4-dichloro-2-butene to give vinylcyclopropanes, which can be thermally rearranged to cyclopentenes (1) (eq 1).1 If the malonates are chiral, optically active cyclopropanes are formed.2 Acetoacetic ester in place of malonate yields cyclohepten-4-one (2) (eq 2) after alkaline hydrolysis.4

cis-1,4-Dichloro-2-butene, on the other hand, yields the cyclopentene exclusively, or a mixture with the vinylcyclopropane, depending on the active methylene compound (eq 3).3

Reactions with vic-diester dianions or with 1,3-dianions afford monocyclic6,7 (3), (4), or fused carbocycles5,8 (5), depending on the anionic compound (eqs 4-6). Bicyclo[4.n.1] ring systems are easily made by use of enolates9 or enamines10 where reactions in the carbonyl form prove difficult.

Carbocycles via Cycloadditions.

[2 + 2] Additions.

Trans-1,4-Dichloro-2-butene adds to fused cyclopentenones to produce a tricyclic system (eq 7).11

Using trans-1,4-dichloro-2-butene, access to anti-tricyclo[,4]hexanes is made very easy.12 The route is via a [2 + 2] addition to maleic anhydride, followed by two intramolecular displacements.

[4 + 2] Additions.

Reactions with anthracene give benzocarbocycles, providing quick access to the triptycenes (eq 8).13

The synthetic utility of these cycloadditions is further enhanced by the base-induced dehydrohalogenation to generate new 1,4-diene units.

cis-1,4-Dichloro-2-butene is easily converted to an electron-rich diene on treatment with sodium aryloxide. This reaction has been used in the synthesis of phyllanthocin (eq 9).14

Synthesis of Heterocycles.

cis-1,4-Dichloro-2-butene affords 1,4-dihydropyrroles with ammonia or amines (eq 10).15,16

Similarly, tetrahydropyridines are accessible using diethyl acetamidomalonates (eq 11).17

1,3-Butadienylphosphonium dichloride (obtained by treating 1,4-dichloro-2-butene with PPh3) reacts with a-mercapto aldehydes or ketones, leading to unexpected vinylthiophenes (eq 12).18

The bis Wittig salt is formed extremely easily with 1,4-dichloro-2-butene, but not with its dibromo counterpart.


This reagent has been made by a novel N to C transannular rearrangement following an intramolecular carbenoid insertion starting from 1,1-dichloro-cis-2,3-bis(chloromethyl)cyclopropane, obtained by dichlorocarbene addition to cis-1,4-dichloro-2-butene.

The reagent is a good source of enyne carbanions,20a generated using Lithium Amide/liq NH3, which can be used for C-C bond formations (eq 13).20b

The reagent also finds use as a coupling promoter to obtain biaryls from aryl Grignard reagents.21

Related Reagents.

1,4-Dibromobutane; 1,4-Dichloro-2-butyne.

1. Quinkert, G.; Weber, W. D.; Schwartz, U.; Stark, H.; Baier, H.; Durner, G. LA 1981, 2335.
2. Quinkert, G.; Schwartz, U.; Stark, H.; Weber, W. D.; Adam, F.; Baier, H.; Frank, G.; Durner, G. LA 1982, 1999.
3. Oediger, H.; Moller, F. LA 1976, 348.
4. Marshall, J. A.; Royce, R. D., Jr. JOC 1982, 47, 693.
5. Bilyard, K. G.; Garratt, P. J.; Underwood, A. J.; Zahler, R. TL 1979, 1815.
6. Christie, J. J.; Varkey, T. E.; Whittle, J. A. JOC 1981, 46, 3590.
7. Ogura, K.; Ishid, M.; Fujita, M. BCJ 1989, 62, 3987.
8. Freed, M. E.; Potoski, J. R.; Freed, E. H.; Conklin, G. L.; Bell, S. C. JMC 1976, 19, 476.
9. Froborg, J.; Magnusson, G.; Thoren, S. JOC 1974, 39, 848.
10. Still, W. C. S 1976, 453.
11. Tobe, Y.; Takahashi, T.; Ishikawa, T.; Yoshimura, M.; Suwa, M.; Kobiro, K.; Kakiuchi, K.; Gleiter, R. JACS 1990, 112, 8889.
12. Wissner, A.; Meinwald, J. JOC 1973, 38, 1697.
13. Hart, H.; Bashir-Hashemi, A.; Luo, J.; Meador, M. A. T 1986, 42, 1641.
14. Burke, S. D.; Cobb, J. E.; Takeuchi, K. JOC 1990, 55, 2138.
15. Palmer, B. D.; Denny, W. A. SC 1987, 17, 60.
16. Brandange, S.; Rodriguez, B. S 1988, 347.
17. Leete, E.; Mueller, M. E. JACS 1982, 104, 6440.
18. McIntosh, J. M.; Seguin, F. P. CJC 1975, 53, 3526.
19. Boswell, R. F.; Bass, R. G. JOC 1977, 42, 2342.
20. (a) Brandsma, L. Preparative Acetylene Chemistry, 2nd ed.; Elsevier: Amsterdam, 1988. (b) Kalyanasundaram, M.; Rajagopalan, K.; Narasimhan, K.; Swaminathan, Indian J. Chem. Sect. B 1979, 17, 97.
21. Taylor, S. K.; Bennett, S. G.; Heinz, K. J.; Lashley, L. K. JOC 1981, 46, 2194.

A. V. Rama Rao

Indian Institute of Chemical Technology, Hyderabad, India

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