Russian Journal of Applied Chemistry, 2009, Vol. 82, No. 11, pp. 1970−1977.
Pleiades Publishing, Ltd., 2009.
Original Russian Text
A.S. Dykman, N.S. Imyanitov, S.A. Polyakov, K.A. Vershinin, 2009, published in Zhurnal Prikladnoi Khimii, 2009, Vol. 82, No. 11,
AND INDUSTRIAL ORGANIC CHEMISTRY
Hydration of Isoprene
A. S. Dykman, N. S. Imyanitov, S. A. Polyakov, and K. A. Vershinin
All-Russia Research Institute of Petrochemical Processes, St. Petersburg, Russia
Eurochim-SPb-Trading, St. Petersburg, Russia
Received March 11, 2009
Abstract—Interaction of isoprene with water in the liquid phase at elevated temperatures and pressures was studied
in the presence of orthophosphoric acid as a catalyst. The products formed and their stability and transformations
were determined. The composition of the compounds formed upon treatment of 3-methyl-2-butenol-1 with acids
The hydration of oleﬁ ns is one of the main methods
for industrial production of alcohols and, therefore, has
been studied in detail. However, data on the hydration of
conjugate dioleﬁ ns are scarce. At the same time, a study
of the hydration of isoprene is of practical interest because
this reaction occurs, as judged from the composition
of the products formed [1, 2], as a side reaction in the
large-tonnage manufacture of isoprene from isobutene
and formaldehyde [3–5].
The addition of water to isoprene at positions 1, 2 and
3, 4 can be described by Scheme 1.
The addition of water at positions 1, 4 can be described
by Scheme 2.
Schemes 1 and 2 do not reﬂ ect mutual transformations
of methylbutenols I, II, V, and VI via allyl rearrangements
because these transformations yield no new products.
The hydration of butadiene and isoprene, catalyzed
by strongly acidic cation-exchange resins, has been
described [6, 7]. Isoprene was converted in aqueous
tetrahydrofuran (at 70–120°C) and sulfolane (at 40°C)
to 2-methyl-3-butenol-2 (I) and 3-methyl-2-butenol-1
(V). In patents, supported phosphoric acid has been
Scheme 1. Possible products of water addition to isoprene at positions 1, 2 and 3, 4