Process for selective reduction of unsaturated organic compounds

A reducible unsaturated organic compound is reduced with diimide in an aqueous emulsion comprised of water, an organic phase which contains the compound to be reduced, and an effective stabilizing amount of an anionic surfactant. The organic compound is preferably an unsaturated organic compound containing a carbon-to-carbon multiple bond, which is preferably a carbon-to-carbon double bond. Diimide is formed by reaction of hydrazine with an oxidant in the aqueous emulsion described above. The preferred oxidant is hydrogen peroxide. A product is obtained in high yield and purity in most cases. This process is especially useful for the selective reduction of a compound having two or more carbon-to-carbon double bonds of different reactivities or a carbon-to-carbon double bond and a functionality (e.g., an O--O or S--S linkage) which is reducible by catalytic hydrogenation but not diimide.

This invention relates to processes for reduction of carbon to carbon 
double bonds in unsaturated organic compounds and in particular to a 
process for the selective reduction of an unsaturated organic compound 
with diimide in an aqueous anionic emulsified medium. 
BACKGROUND ART 
It is known that rubber latexes, especially nitrile-butadiene rubber (NBR) 
latexes can be directly reduced in the latex form to the saturated analog 
(HNBR) in the presence of hydrazine, an oxidizing agent and a metal ion 
initiator. Such reaction is disclosed in U.S. Pat. No. 4,452,950 to 
Wideman. Even with large excesses of hydrazine, reductions are not 
quantitative and there is a wide range, from 20% to 83% olefinic 
reduction, in the examples given. This patent states that the polymer be 
prepared in an aqueous emulsion polymerization and be reduced in the latex 
form without prior coagulation or use of organic solvents. Use of a 
surfactant in emulsion polymerization is standard procedure and it is 
believed that an anionic surfactant as used, even though surfactant is not 
mentioned. This patent and the instant application are commonly assigned. 
Hunig et al "The Chemistry of Diimide", Angewandte Chemie. International 
Edition, vol. 4, no. 4, April, 1965, pps. 271-280, describes methods for 
generating diimide (which this reference refers to as diimine) and to 
reactions of diimide with compounds containing one or more 
carbon-to-carbon double bond. Also described are decomposition of one mole 
of diimide into nitrogen and hydrogen, and disproportionation of two moles 
of diimide into nitrogen and hydrazine (these are competing reactions, as 
disclosed in the reference). Substrate specificity of hydrogenation, (i.e. 
multiple bonds which do not react with diimide) and competition between 
olefin hydrogenation, and between disproportionation and olefin 
hydrogenation, are also described. Reactions described were carried out in 
solution. 
Organic Syntheses, collective vol. V, H. E. Baumgarten, Editor, John Wiley 
& Sons, Inc. 1973, pp 281-290, describes reduction of 
cis,trans,trans-1,5,9-cyclododecatriene to cis-cyclododecene with 
hydrazine and air in an ethanol solution containing copper sulfate. 
Product recovery includes filtration, extraction of the filtrate with 
petroleum ether, and distillation. A yield of 64-80 percent and a purity 
of about 80-90 percent are reported. 
Organic Reactions, vol. 40, L. A. Paquette et al., Editors, John Wiley & 
Sons, Inc. 1991, pp 91-155, is a compilation of previously published 
procedures for generation of diimide and for reaction of diimide with 
compounds containing a carbon-to-carbon double bond. Relative reactivity 
of double bonds, stereoselectivity, and groups (such as N--O) which can be 
reduced with other reducing agents but not with diimide, are also noted. 
This article contains a number of specific experimental procedures, (all 
taken from earlier published literature) showing reduction of various 
substrate compounds containing carbon-to-carbon double bonds with diimide. 
Reduction of a number of additional substrate compounds is shown in 
tables. Reactions are carried out in solution, using organic solvents for 
the most part. The reference notes the need to use large excesses of 
diimide, owing to disproportionation and other side reactions. 
DISCLOSURE OF THE INVENTION 
This invention provides a process for reducing one or more carbon-to-carbon 
double bonds in an unsaturated organic compound containing the same, which 
comprises contacting the unsaturated organic compound with a diimide 
reducing agent in an anionically emulsified aqueous medium and in the 
presence of an oxidant and a metal oxide initiator. 
The preferred diimide reducing agent is hydrazine or a hydrazine hydrate. 
Reduction according to this invention is selective. Allylic and benzylic 
functions do not undergo a hydrogenolysis with the diimide, nor are 
sensitive hetero atom bonds such as N--N, N--O, O--O, S--S or C-halogen 
destroyed. 
The present invention more specifically reveals a process for reducing a 
reducible carbon-to-carbon multiple bond in an unsaturated organic 
compound containing the same which comprises contacting said organic 
compound with hydrazine or a hydrate thereof and an oxidant in an emulsion 
comprising water, an effective amount of a metal ion initiator, a water 
immiscible organic phase containing said organic compound, and an 
effective stabilizing amount of an anionic surfactant.

DETAILED DESCRIPTION 
The starting material (or substrate) is an unsaturated organic compound 
having one or more carbon-to-carbon double bonds, or alternatively one or 
more carbon-to-carbon triple bonds (or both). The organic compound may be 
either acyclic, carbocyclic or heterocyclic. The compound is a monomer 
(whether or not capable of homopolymerization) as opposed to a dimer, 
oligomer or polymer. The compound may have functionalities which are 
reducible by means other than the oxidant/reducing agent combination 
herein; in fact, one of the important advantages of the present process is 
that it gives a clean and (in most cases) quantitative or nearly 
quantitative reduction of non-aromatic carbon-to-carbon unsaturations 
while leaving certain other groups untouched. The molecular weight of the 
starting organic compound is typically no more than 1000 and generally no 
more than 500. Additionally, the organic compound does not contain any 
repeating monomeric units. 
Allylic and benzylic functions do not undergo cleavage reactions with 
diimide according to this invention. Similarly, hetero atom bonds such as 
N--N, N--O, and O--O, which often suffer reductive cleavage under 
catalytic hydrogenation conditions, remain intact during diimide reduction 
according to this invention. Therefore, the process of this invention is 
especially well suited to reduction of carbon-to-carbon double or triple 
bonds in compounds which also contain any of these functionalities. 
Functionalities which are susceptible to reduction by other means but 
resistant or inert to attack by diimide are known in the art, as 
illustrated for example in the non-patent literature references cited 
earlier herein. Functionalities which are inert to diimide in solution are 
also inert to diimide in emulsion reaction procedures according to this 
invention. 
It is also known in the art, as illustrated in the non-patent literature 
cited earlier herein, that certain carbon-to-carbon double bonds are more 
reactive than others. Selective reduction of the more reactive double bond 
is facile in emulsion in accordance with this invention. On the other 
hand, selective reductions with diimide in solution are difficult, as 
noted in Organic Reactions, cited supra at page 96, owing to the need to 
use large excesses of diimide. 
The reducing agent of this invention is diimide, N.sub.2 H.sub.2, which may 
be formed in situ as will be described hereinafter. Diimide has three 
isomeric forms, i.e., cis-diimide, trans-diimide and 1,1-diimide as 
described in Organic Reactions, cited supra, at pages 92 and 93. 
Various reagents and reagent combinations which will generate diimide in 
situ are disclosed in "Organic Reactions" on pages 99 and 100. A preferred 
reagent combination is the combination of hydrazine and an oxidizing agent 
(or oxidant) and in particular a combination of molecular oxygen (e.g., 
air) or a peroxide (especially hydrogen peroxide) and hydrazine. The term 
"hydrazine", will be used herein to denote anhydrous hydrazine and the 
hydrates, of which the monohydrate is the most common. 
The oxidizing agent may be either molecular oxygen (air or oxygen enriched 
air or pure oxygen), hydrogen peroxide (which may be an aqueous solution), 
or an organic hydroperoxide. Representative hydroperoxides are cumyl 
hydroperoxide, t-butyl hydroperoxide and p-menthane hydroperoxide. Other 
commercially available oxidants that are known to oxidize hydrazine 
include iodine, iodate ion, hypochlorite ion, ferricyanide ion and the 
like. The classes of oxidants disclosed herein are essentially the same as 
those disclosed in U.S. Pat. No. 4,452,950 cited supra. A common 
characteristic shared by molecular oxygen, hydrogen peroxide and the 
hydroperoxides is that all have an O--O bond. 
When the oxidant is either molecular oxygen or hydrogen peroxide, a metal 
initiator, which may be either a metal ion or a metal salt, is required. 
Suitable metal initiators are disclosed in U.S. Pat. No. 4,452,950. 
Representative metals whose ions or salts will react with hydrazine and 
are, therefore, useful in the present invention are as follows: 
______________________________________ 
Antimony Arsenic Bismuth 
Cerium Chromium Cobalt 
Copper Gold Iron 
Lead Manganese Mercury 
Molybdenum Nickel Osmium 
Palladium Platinum Polonium 
Selenium Silver Tellurium 
Tin Vanadium 
______________________________________ 
The copper ion is a particularly useful metal initiator, and is 
conveniently supplied in the form of aqueous copper sulfate. The 
concentration of metal ion initiator is not critical and usually only very 
small amounts are required. Reduction according to this invention is 
carried out in an emulsion which comprises an aqueous phase and an organic 
phase. The aqueous phase, which is the continuous phase, comprises water, 
an anionic surfactant (to be described below), and a metal initiator 
(described above). The organic phase contains the organic substrate 
compound to be reduced, and in many cases, the substrate is the sole 
constituent of the organic phase, other than the hydrophobic moiety 
(moieties) of the surfactant(s). Essential to the success of the present 
process is the presence of an anionic surfactant in the aqueous medium. 
Commercially available anionic surfactants may be used. A preferred 
anionic surfactant is "Dowfax" 2A1, which is a branched C.sub.12 alkylated 
diphenyloxide disulfonic acid disodium salt. Other classes of suitable 
anionic surfactants include the following: 
Alkylaryl Sulfonates: "Witconate.TM." LX Flakes--(Witco Corp.) and 
"Siponate" DDB-40--(Rhone-Poulenc). 
Sulfonated Amines and Amides: "Emlcupon" L--(Emkay Chemical Company) and 
"Indulin" MQK--(Westvaco Corp.). 
Amphoteric Betaine Derivatives: "Alkateric.TM." CB--(Rhone - Poulenc) and 
"Schercotaine" MAB--(Scher Chemicals, Inc.). 
Diphenyl Sulfonate Derivatives: "Dowfax" 2A1--(Dow Chemical Company) and 
"Poly-Tergent" 2A--(Olin Corporation). 
Ethoxylated Fatty Acids: "Chemax" ML--(Chemax, Inc.) and "Hodag L"--(Hodag 
Chemical Corporation). 
Olefin Sulfonates: "Bio-Terge" AS-40--(Stepan Company) and "Siponate" 
A246L--Rhone - Poulenc). 
Sulfates and Sulfonates of Ethoxylated Alkyl Phenols: "Aerosol" 
NPES--(American Cyanamid) and "Polystep" F-2--(Stepan Company) 
Sulfates and Sulfonates of Oils and Fatty Acids: "Dymsols"--(Henkel 
Corporation) and "Eureka" 102--(Atlas Refinery, Inc.) 
Sulfates: "Duponol" QC--(DuPont) and "Sandoz Sulfate"--(Sandoz Chemical 
Corporation) 
Sulfates of Ethoxylated Alcohols: "Texapon" ASV--(Henkel Corporation) and 
"Carsonol.RTM." SES-A--(Lonza, Inc.) 
Sulfates of Fatty Esters: "Emkafol"--(Emkay Chemical Company) and 
"Sulfonated GTO"--(National Starch & Chemical). 
Sulfonates of Condensed Naphthalenes: "Erional.RTM."--(Ciba-Geigy 
Corporation) and "Harol" RG--(Graden Chemical). 
Sulfosuccinates and Derivatives: "Aerosol" OT--(American Cyanamid) and 
"Incrosul" LTS--(Croda, Inc.). 
Sulfosuccinamates: "Aerosol" 22--(American Cyanamid) and "Octosol" 
A-1--(Textile Rubber & Chemical Company). 
Sulfonates of Dodecyl and Tridecylbezenes: "Bio-Soft" N-300--(Stepan 
Company) and "Witconate.TM." 60B--(witco Corporation). 
As is true generally of surfactants, the surfactants herein have a 
hydrophilic moiety and a hydrophobic moiety. 
An effective stabilizing amount of the anionic surfactant is used. The 
term, "effective stabilizing amount" denotes an amount of surfactant 
sufficient to maintain a stable aqueous emulsion. As those skilled in the 
art will recognize, most or nearly all of the unsaturated organic 
compounds which are reducible in accordance with this invention are 
immiscible in water. The amount of surfactant is not critical and is 
typically from about 0.5 to about 15 parts by weight per 100 parts of 
organics. 
The amount of surfactant required may be determined empirically for each 
system. 
Use of a stabilizing amount of an anionic surfactant is essential to the 
success of the present process. Similar results are not obtained with a 
cationic surfactant or a nonionic surfactant. 
A mildly alkaline medium, e.g. one having a pH from about 8 to about 12 is 
used to carry out reduction according to this invention. The pH will 
usually and preferably be in the range of 9.5 to 10.5. 
In some cases it may be desirable to use an organic co-solvent, for 
instance, when the substrate is a solid. The co-solvent should have low 
water miscibility and be unreactive toward hydrazine and oxidants. 
Suitable co-solvents include toluene, xylene, hexane and heptane. The 
purpose of a co-solvent is to dissolve non-liquid (solid) substrates and 
aid in their emulsification. The amount of co-solvent (when used) may 
range from about 0.5 to about 10,000 parts by weight per 100 parts of 
unsaturated carbon compound. The actual amount of co-solvent required is 
dependent on the solubility of the substrate in the chosen solvent. 
Reduction of double or triple bonds in unsaturated organic compounds in 
accordance with the present invention is essentially quantitative or 
nearly quantitative when carried out in an emulsified aqueous/organic 
medium in accordance with this invention. In addition, reduction 
efficiency based on hydrogen peroxide consumed, approaches theoretical 
quantity (1 mole of double bond reduced for each mole of hydrogen peroxide 
consumed). In nearly all cases, reduction efficiency is at least about 80 
percent and in most cases is at least about 85 percent. (A reduction 
efficiency of 85 percent represents 0.85 mole of reduction product for 
each mole of hydrogen peroxide consumed). In short, side reactions occur 
to a remarkably small extent. Conversion of the starting material or 
substrate to desired reduction product (or products) is usually nearly 
quantitative. Analysis of the reaction product typically shows that nearly 
all of the starting material can be accounted for, either as one or more 
reduction products or unreacted starting material. This is in marked 
contrast to earlier known processes, including those described in "Organic 
Reactions" (published 1991) and other prior art references, wherein 
reduction is carried out in solution and an excess, and usually a 
substantial excess, of hydrazine and oxidant (or other reagent or reagent 
combination yielding diimide) is required. In fact, results in this regard 
are as good as, or even better than, the results in reducing &gt;C.dbd.C&lt; 
double bonds in rubber latexes, as described in U.S. Pat. No. 4,452,950 
cited supra. 
Furthermore, quantitative or nearly quantitative reduction of 
carbon-to-carbon multiple bonds is obtained according to the present 
invention without regard to the hydrazine concentration in the preferred 
reaction system. Prior art process in which a hydrazine/oxidant 
combination is used, become less efficient, with a proportionately greater 
amount of side reactions taking place, as the diimide concentration 
increases. This means that the prior art processes must generate very low 
concentrations of diimide in order to achieve reduction without undue side 
reactions taking place. 
No one prior to the present invention has applied the emulsion reduction 
technique as described herein to the reduction of unsaturated organic 
compounds, as far as applicant is aware even through U.S. Pat. 
No.4,452,950 (relating to reduction of double bonds in rubber latexes 
formed by emulsion polymerization) was issued in 1984. Attention is called 
to "Organic Synthesis" (1991) cited supra in this regard. The unsaturated 
polymer latex systems described in U.S. Pat. No. 4,452,950 include an 
anionic surfactant, even though such surfactant is not specifically 
mentioned. 
While applicant does not wish to be bound by any theory of reaction or by 
any explanation as to why outstanding results are obtained according to 
the present invention, in contrast to the poor results previously obtained 
when reducing unsaturated organic compounds, applicant believes that the 
most probable explanation is that given below. 
Hydrazine reacts with an oxidizing agent or oxidant, e.g., molecular oxygen 
or hydrogen peroxide to yield diimide (referred to diimine by some 
authors) according to equation (1) below. 
EQU H.sub.2 N--NH.sub.2 +[O].fwdarw.[HN.dbd.NH] (1) 
When the oxidant is hydrogen peroxide, the formation of diimide may be 
represented by equation (1a) below. 
EQU H.sub.2 N--NH.sub.2 +H.sub.2 O.sub.2 .fwdarw.[HN.dbd.NH]+2H.sub.2 O (1a) 
The resulting diimide, which is an unstable intermediate and therefore 
bracketed in equation (1), then reacts with a carbon-to-carbon double bond 
according equation (2). 
EQU HN.dbd.NH+&gt;C.dbd.C&lt;.fwdarw.N.sub.2 +&gt;CH--CH&lt; (2) 
Acetylenic compounds, i.e., compounds having a carbon-to-carbon triple 
bond, react in an analogous manner except that stepwise reduction is 
possible. Two moles of reducing agent per mole of acetylenic compound 
accomplish a complete reduction of the triple bond to a single bond. One 
mole of reducing agent per mole of acetylenic compound reduces the triple 
bond to a double bond. 
Side reactions may occur to a limited extent. The principal side reaction 
is the bi-molecular disproportionation according to equation (5) below, 
with the monomolecular decomposition shown in equation (4) being 
relatively minor. 
EQU HN.dbd.NH.fwdarw.N.sub.2 +H.sub.2 (4) 
EQU 2HN.dbd.NH.fwdarw.N.sub.2 +H.sub.2 N--NH.sub.2 (5) 
Reaction (5) is the main competing reaction to the process shown in 
equation (2). The rate of the disproportionation reaction (5) in 
homogeneous solutions increases with the square of the diimide 
concentration whereas the rate of reaction (2) (olefin hydrogenation) 
increases with the first power of the diimide concentration. Therefore, 
the yield of the hydrogenated product will be reduced under all conditions 
leading to an increase in the diimide concentration. Applicant finds 
remarkably that this is not the case with the anionically emulsified 
reaction systems of this invention. While applicant does not wish to be 
bound by any theory of reaction, a possible and even probable explanation 
is given below. 
When a molecule of unsaturated organic compound collides with a diimide 
molecule, a carbon-to-carbon bond in the unsaturated compound will be 
reduced in accordance with equation (2) above. (An analogous reaction will 
take place if the carbon-to-carbon bond is a triple bond instead of a 
double bond as shown). If on the other hand one diimide molecule collides 
with another diimide molecule, reaction (5) takes place and diimide is 
consumed without any useful reduction of a carbon-to-carbon bond. It is 
known that emulsified systems create a multiplicity of microscopic 
particles, typically from about 30 to about 5000 nanometers (nm) in 
diameter. Each such particle of unsaturated organic compound is believed 
to function like an individual reactor which is isolated from all of the 
other individual particles or "reactors" in the system. This greatly 
increases the probability of reaction of a diimide molecule with a 
molecule of unsaturated organic compound in accordance with equation (2) 
and correspondingly decreases the probability and extent of side reaction 
(5). 
This invention will now be described further with reference to the specific 
examples which follow. 
EXAMPLE I 
Diimide reduction of cis,trans,trans-1,5,9-cyclododecatriene (I) in 
emulsion 
The title reduction may be depicted by the equation below: 
##STR1## 
Reactants include hydrazine and hydrogen peroxide in addition to 
cis,trans,trans-1,5,9-cyclododecatriene (I), which is shown. 
T A: Preparation of Cyclododecatriene Emulsion 
A 600 mL beaker was charged with 150 g deionized water, 100 g of 91% pure 
1,5,9-cyclododecatriene and 5.0 g of stearic acid. The resulting mixture 
was heated to 75.degree.-80.degree. C. to melt stearic acid and was 
intensively mixed at this temperature using a high shear Tekmar agitator 
while adding sufficient 50% aq. KOH to raise the pH to 10.5-11.0. The 
emulsion was cooled to room temperature and allowed to stand overnight. 
(Note: density differences between bulk water and emulsified particles 
caused some separation overnight, but gentle mixing again gave a uniform 
emulsion). The final emulsion contained 39.2 percent 
1,5,9-cyclododecatriene (I) by weight. 
T B: Diimide Reduction 
Into a 250 mL neck round bottom flask, equipped with a mechanical stirrer, 
thermometer, heating mantle and feeding tube for hydrogen peroxide, the 
following were charged in the order named: 
(a) 76.53 g of 1,5,9-cyclododecatriene emulsion (ca. 0.1685 moles of 
cyclododecatriene or 0.5057 moles of double bonds). 
(b) 2 ml of copper sulfate pentahydrate/"Dowfax" 2A1 solution, prepared by 
dissolving 0.385 g (0.00154 moles) of copper sulfate pentahydrate, 7.5 g 
(ca. 0.00592 mols) of 45 percent active "Dowfax" 2A1 (which is a branched 
C.sub.12 alkylated diphenyloxide disulfonic acid disodium salt) in 92 mL 
of tap water. 
(c) 27.55 g of 64 percent aqueous hydrazine (0.5544 moles). 
Then 57.12 g of 33 percent aqueous hydrogen peroxide (0.5544 moles) was 
slowly added dropwise over several hours at a rate sufficient to keep the 
reaction temperature between 60.degree. and 65.degree. C. (Actually a 
total of 0.68 moles of hydrogen peroxide was added. The samples of the 
reaction mixture showed very little change in composition after 0.5544 
moles was added). No defoamer was used and no foaming was observed during 
the run. Samples of the reaction mixture were analyzed periodically during 
the course of reaction as hydrogen peroxide was added. 
TABLE 1 below shows the progress of diimide emulsion reduction of 
1,5,9-cyclododecatriene (I) in accordance with Example 1 as hydrogen 
peroxide is added. As TABLE 1 shows, the reactant 1,5,9-cyclododecatriene 
(I) is steadily consumed as hydrogen peroxide is added, the quantity 
remaining reaching essentially 0 when about 0.53 moles (corresponding to 
about 95-96 percent of the theoretical quantity) of hydrogen peroxide had 
been added. Further addition of hydrogen peroxide causes little change in 
either the quantity of reactants still present or of the quantities of 
either product compound. The quantity of cyclododecene (II) goes through a 
maximum after approximately 0.24-0.34 moles of hydrogen peroxide have been 
added and thereafter decreases as more cyclododecane (III) is formed. 
Percentage conversion shown in TABLE 1 are GC (gas chromatography) area 
percentages. From the GC results shown in TABLE 1, it is estimated that a 
total of 0.4825 moles of double bonds were reduced out of the original 
0.5057 moles present (95% reduction) with 87 percent of the product being 
cyclododecane (III) and 12.6 percent being cyclododecene (II). This 
represents a hydrazine consumption ratio of about 1.15, i.e., about 1.15 
moles of hydrazine consumed per mole of double bonds converted. This is 
arrived at as follows: 0.5544 moles hydrazine/0.4825 of double bonds 
converted= 1.15. The double bond reduction efficiency which is the 
reciprocal of the hydrazine conversion ratio, is about 87 percent. 
TABLE 1 
______________________________________ 
Diimide emulsion reduction of 1,5,9-Cyclododecatriene (I) 
Reaction mixture 
Moles H.sub.2 O.sub.2 
Mole % I Mole % II Mole % III 
added (substrate) (product) (product) 
______________________________________ 
.05 84 16 trace 
.10 68 29 3 
.15 54 38 8 
.20 44 43 11 
.25 35 47 17 
.34 21 48 31 
.44 8 40 51 
.48 5 34 60 
.53 1 15 84 
.58 0 13 87 
.68 0 13 87 
______________________________________ 
Note: 
Compounds in TABLE 1 are as follows: 
I = 1,5,9cyclododecatriene (starting material) 
II = cyclododecene (a product) 
III = cyclododecane (the principal product) 
EXAMPLE II 
Diimide reduction of vinyl cyclohexene in emulsion T A. Preparation of 
Emulsion 
An emulsion of vinyl cyclohexene (IV) (100 g) was prepared in the same 
manner and using the same equipment as described in example I, part A, 
except that vinyl cyclohexene was substituted for 1,5,9-dodecatriene. 
T B. Diimide Reduction Procedure 
Into a 250 mL 3 neck round bottom flask, equipped with a mechanical 
stirrer, thermometer, heating mantle and peroxide inlet tube, the 
following were charged in the order named: 
(a) 69.78 g (0.2528 mols) of vinyl cyclohexene emulsion. 
(b) 2 ml of copper sulfate/"Dowfax" 281 solution (same composition as in 
Example 1). 
(c) 27.55 g (0.5544 moles) of hydrazine. 
The above mixture was heated to 64.degree. C. Over a seven hour period, 
57.12 g (0.5544 moles) of 33 percent aqueous hydrogen peroxide was added 
dropwise at such rate as to keep the reaction temperature between 
60.degree. and 65.degree. C. The reaction product was analyzed by gas 
chromatography (GC). 
The amount of reaction product (designated as "Unknown I") increased nearly 
linearly and the amount of vinyl cyclohexene starting material decreased 
correspondingly nearly linearly as hydrogen peroxide was added. 
The final product contained 40 percent by weight of "unknown I" and 60 
percent of unreacted vinyl cyclohexene. While "Unknown I" was not analyzed 
and is therefore characterized as an unknown, it is believed that this 
compound is in fact ethyl cyclohexene. The fact that only one unknown was 
found in the product indicates that only one of the two double bonds in 
the starting vinyl cyclohexene was reactive under the conditions used; the 
other double bond (believed to the cyclic olefin, which did not 
effectively compete with the pendent vinyl double bond) was inert. 
EXAMPLE III 
Diimide reduction of 7-methyl-1,6-octadiene in emulsion. 
T A: Preparation of emulsion 
An emulsion of 100 g of 7-methyl-1,6-octadiene was prepared in the manner 
described in Example 1, T A, except that 7-methyl-1,6-octadiene was 
used instead of 1,5,9-cyclododecatriene. 
T B: Diimide reduction 
The procedure of Example 1, Part B was followed except that 79.97 g of the 
emulsion prepared in part A (containing 0.2524 mols of 
7-methyl-1,6-octadecadiene) was used in place of the emulsion described in 
Example 1. 
Samples were taken and analyzed by GC during the course of hydrogen 
peroxide addition and when all hydrogen peroxide addition was complete. 
Amounts of product increased almost, but not quite linearly, and amounts 
of starting material correspondingly decreased almost but not quite 
linearly as hydrogen peroxide was added. The final product, as shown by GC 
analysis, contained about 78 percent of 2-methyl-2-octene and about 19 
percent of unreacted starting material. Presence of only one reaction 
product and the high degree of accountability (about 97 percent) shows 
that only one of the two double bonds in the starting material was 
reactive, the other being inert. 
EXAMPLE IV 
Diimide reduction of dicyclopentadiene 
T A: Preparation of emulsion 
An aqueous emulsion containing 100 g of 
3a,4,7,7a-tetrahydro-4,7-methano-1H-indene (CAS registry no. 77-73-6, also 
known as "dicyclopentadiene") was prepared in the manner described in 
Example I, part A. 
T B: Diimide reduction 
The procedure of Example I, part B, except that 85.26 g of the emulsion 
prepared in part A was used instead of the emulsion described in Example 
I. This emulsion contained 0.2527 moles of dicyclopentadiene. 
Reaction product samples were analyzed periodically by GC as hydrogen 
peroxide was added and when hydrogen peroxide addition was complete. 
The amount of starting material decreased almost linearly and the amount of 
"Unknown Number I" increased almost linearly until about 46 grams of 
hydrogen peroxide (representing about 88 percent of the theoretical amount 
required for reduction of both double bonds in the starting material) had 
been added. At this point the reaction mixture contained about 99 percent 
of "Unknown I", about 1 percent of "Unknown II" and substantially no 
starting material, as shown by GC analysis. When addition of hydrogen 
peroxide was complete, the reaction product contained about 88 percent of 
"Unknown I" and about 12 percent of "Unknown II" and substantially no 
starting material. It is believed that "Unknown I" is 
3a,4,5,6,7,7a-hexahydro-4,7-methano-1H-indene (CAS no. 4488-57-7) and that 
"Unknown II" is 1,3,4,5,6-octahydro-4,7-methano-1H-indene (CAS no. 
6004-38-2). 
The foregoing examples are illustrative of the types of unsaturated 
compounds that can be reduced with diimide according to the present 
invention. These examples are not intended to be exhaustive. Suitable 
types of compounds which can be reduced according to the present invention 
have been described earlier in the specification. 
The foregoing examples show that reduction of double bonds in aqueous 
emulsion with diimide according to the present invention is nearly 
quantitative (since the quantity of hydrogen peroxide was about 10 to at 
most 15 percent in excess of stoichiometric in the above examples) which 
is in marked contrast to the much poorer results obtained when reducing an 
unsaturated organic compound with diimide in solution. The examples also 
show that, in many cases, a compound containing two double bonds may be 
reduced selectively, only one of the double bonds being reduced while the 
other remains intact. Examples II, III, and IV illustrate this. Where such 
selectivity exists (and this has been discussed earlier in this 
specification) the present process affords a superior alternative to 
catalytic hydrogenation, in which all double bonds are reduced. Also, as 
noted earlier, certain diatom difunctionaltities (heteroatom bonds) such 
as N--N, N--O, and others noted earlier, are destroyed by catalytic 
hydrogenation but are inert to diimide reduction. All percentages are by 
weight unless expressly stated otherwise. 
While this invention has been described in detail with particular reference 
to specific embodiments thereof, it shall be understood that such 
description is by way of illustration and not limitation.