Organic Reactions Volume 4 - Sciencemadness Dot Org

DIENE SYNTHESIS I 15
Mesaconic (methylfumaric) acid.
Itaconic anhydride.
Di- and tetra-hydrophthalic anhydrides.
Dihydronaphthalenedicarboxylic anhydrides.
Dihydrophenanthrenedicarboxylic anhydrides.
3,4-Dihydro-8,9-acephenanthrene-l,2-dicarboxylic anhydride.
Reaction with Acyclic Compounds. Butadiene reacts with maleic
anhydride in benzene solution at 100° to give a quantitative yield of
m-l,2,3,6-tetrahydrophthalic anhydride (XVI). B - 147 ' 148 Mono-, di-, and
tri-alkylbutadienes, as well as 2-acetoxybutadiene, 2-formoxybutadiene
CH2
CH CHOf .
CH CHC< l
CH2
CO
J P
x co
(formoprene), 2,3-dimethoxybutadiene, butadienyl thioethers, chloroprene,
and bromoprene react in a similar manner (see Table III). The
reaction usually proceeds readily at room temperature when the components
are mixed in equivalent proportions, and a quantitative yield
of the corresponding adduct is often obtained. Fatty acids containing
conjugated systems likewise add maleic anhydride readily.* Certain
halogenated dienes are, however, inert toward maleic anhydride. Thus,
2,3-dichloro-l,3-butadiene, l,3,4,6-tetraehloro~2,4-hexadiene, 3,6-dichloro-l,3,4-hexatriene,
3,4,6-trichloro-l,2,4-hexatriene, 4-chloro-l,2,3,5-hexatetraene,
and 3,4-dichloro-l,2,4,5~hexatetraene fail to react, though it
has been shown that 1,4-addition to a conjugated system terminating
in a series of contiguous double bonds is possible. 149 ' 150
The Diels-Alder reaction provides a convenient route for the synthesis
of biphenyl, terphenyl, and quaterphenyl derivatives. l,4~Diphenyl-
1,3-butadiene, for example, reacts readily with maleic anhydride to give
the hydroterphenyl derivative XVII. 161 Hydrobiphenyl systems have
also been prepared successfully by the addition of butadienes to cinnamaldehyde,
6 benzylidenemalonic ester, 51 or styrene, 65 and by the thermal
polymerization of butadiene itself. 74 An adduct of type XVII may be
* This reaction sometimes yields elastic or resinous condensation products of industrial
value. See C. A., 27, 4890 (1933); C. A., 29, 5953 (1935); C. A., 30, 6848 (1936); C. A.,
32, 2248 (1938).
147 Diels and Alder, Ber., 62, 2087 (1929).
148 Farmer and Warren, J. Chem. Soc, 1929, 897.
149 Berchet and Carothers, /. Am. Chem. Soc, 55, 2004 (1933).
160 Coffman and Carothers, J. Am. Chem. Soc, 55, 2040 (1933).
161 Diels, Alder, and Pries, Ber., 62, 2081 (1929).
XVI