Linear and cyclic sucrose reaction products, their preparation and their use

Sucrose ester and ether products, useful as food or beverage bulking agents, reduced calorie sweeteners, fat replacement agents, stabilizing agents, thickening agents and emulsifying agents; adhesives; biodegradable plastics and films; sizing agents for paper and textiles; ethical pharmaceuticals and new fibers are prepared by using a two-phase reaction system in which sucrose is dissolved in an alkaline, aqueous solution and an acidic reagent such as a bifunctional acid dichloride or epoxide is added to the sucrose in a water-immiscible organic solvent. Several types of products are produced: water-insoluble sucrose ester (ether) copolymers; water-soluble sucrose ester (ether) copolymers; sucrose ester (ether) dimers; and intramolecular, cyclic sucrose esters (ethers). These products can be further varied by using different kinds of acid dichlorides or epoxides that contain different kinds of functional groups. The reaction proceeds at the interface of the water/organic solvent solutions whereby there is imparted a specificity that restricts the reaction to the 6 and 6' primary alcohol groups of sucrose. The reactions can be selected for each of the four basic types of products by controlling the various reaction parameters.

FIELD OF THE INVENTION 
This invention relates to new and useful sucrose derivatives, the 
particular methods for their syntheses, and the use of the products. 
BACKGROUND OF THE INVENTION 
The most abundant pure organic chemical in the world is sucrose. See 
Kirk-Othmer, Encyclopedia of Chemical Technology, 3d Edition, Volume 21, 
John Wiley & Sons, New York, pages 921-948 (1983). However, although 
sucrose produced from sugar cane and sugar beets is ubiquitous in its 
availability and is of relatively low cost, only a fraction of a percent 
by weight is consumed as a chemical feedstock. The potential value of 
sucrose as a raw material has been recognized for many years and has been 
the subject of considerable research. 
Sucrose is a particularly appropriate material for use in the formation of 
esterified products produced currently from petroleum-based materials 
because (a) it is a naturally occurring, relatively abundant renewable 
material; (b) it is polyfunctional with three reactive primary alcohols 
that can readily be derivatized; (c) it is a nonreducing sugar and thus 
does not have the potential for the wide variety of side-reactions that 
reducing sugars have; (d) it has a relatively easily hydrolyzed glycosidic 
linkage that allow sucrose polymers to be potentially more biodegradable 
than polymers made with other carbohydrates, such as sugar alcohols; and 
(e) it is a naturally occurring sweet carbohydrate in common use and 
therefore potentially useful in the formation of potential non-absorbable, 
noncaloric sweeteners. 
The usual technique for the synthesis of carbohydrate esters involves a 
reaction of the carbohydrate with an acid chloride or acid anhydride in a 
basic organic solvent, such as triethylamine, pyridine or quinoline. In a 
few instances, the organic base has been replaced by sodium hydroxide. 
However, the prior art teaches very little about the reaction of sucrose 
with polyfunctional reagents. 
Although relatively few successful derivatives of sucrose have been 
commercialized, there has been substantial interest in developing 
sugar-based synthetic technology. Thus, in 1953, Sonntag, in Chemical 
Reviews52 at page 321, described a technique where a polyhydroxy compound 
was dissolved in a large excess of a tertiary amine, and by adding thereto 
an acid chloride, preferably in a solvent such as chloroform. However, 
only mixtures in low yields were obtained which were not easy to separate. 
On the other hand, the preparation of pure regiospecific esters of 
polyhydric alcohols (carbohydrates) is a more complicated problem 
requiring special innovation, such as prior to reaction, the blocking of 
certain hydroxyl groups in the polyalcohol with easily removable groups. 
In the patented literature, U.S. Pat. No. 2,927,919 relates to ether-esters 
of sucrose, U.S. Pat. No. 3,170,915 discloses sucrose ethers and U.S. Pat. 
No. 3,300,474 discloses the preparation of sucrose ether co-polymerizates. 
SUMMARY OF THE INVENTION 
It is accordingly one object of the present invention to provide a new 
group of ester and ether derivatives of sucrose. 
It is a further object of the invention to provide a novel class of sucrose 
esters and ethers which are useful as food bulking agents, reduced calorie 
sweeteners, fat replacement agents for food products, stabilizing agents 
for food and beverage products, thickening and emulsifying agents for food 
products, adhesives, biodegradable plastics and films, sizing agents for 
paper and textiles, ethical pharmaceuticals and new fibers. 
A still further object of the present invention is to provide a method for 
the preparation of sucrose esters which enables preparation of the sucrose 
esters in high yields and with improved specificity over methods known to 
the prior art. 
Other objects and advantages of the present invention will become apparent 
as the description thereof proceeds. 
The present invention comprises the use of various bifunctional reagents 
such as dicarboxylic acid dichlorides, epichlorohydrin, phosphorus 
oxychloride, and diphosphoryl tetrachloride for the formation of sucrose 
derivatives. The sucrose products disclosed herein are embraced by the 
following formula: 
EQU Suc-R(-Suc-R-).sub.x Suc 
wherein Suc is a sucrose molecule attached to a connector group R at the 
6,6-,6,6'-, or 6',6'-positions of the sucrose in which x ranges from 0 up 
to about 500, and R is a radical which is the residue of a bifunctional 
acidic reactant. Preferably, R is a hydrocarbylacyl or hydrocarboyloxy 
radical or a phosphorous radical wherein the hydrocarbylacyl portion may 
be saturated or unsaturated aliphatic, cycloaliphatic, or aromatic, and 
may be further substituted by one, two, three or more other groups such as 
amino, hydroxyl, halogen, alkyl, alkyl substituted amino, or the like. By 
hydrocarbylacyl is meant a hydrocarbon portion of the type specified 
having two carbonyl functional groups attached to sucrose. 
Preferably R is a radical selected from the group consisting of: 
##STR1## 
and the corresponding alkali metal and alkaline earth metal salts wherein 
m is O up to about 10, preferably 0 to about 6, and each of R.sup.1 and 
R.sup.2 independently is H, or C.sub.1 -C.sub.4 alkyl or one of R.sup.1 
and R.sup.2 can also be OH or CH.sub.2 OH. 
To prepare the sucrose derivative of this invention, sucrose is reacted 
with a bifunctional reactant preferably of the formula X-R-X, wherein R is 
as defined above and X is a functionally reactive group such as a halogen, 
under special reaction conditions as described hereinafter. The preferred 
halogen is a chlorine group. The reaction is performed by the slow 
addition of a bifunctional reagent such as an acyl dichloride, dissolved 
in a substantially water immiscible organic solvent, to an alkaline 
aqueous solution of sucrose. The reaction proceeds at the interface 
between the two immiscible solutions to provide an interfacial 
condensation and produce the sucrose derivative or analogue. It has been 
discovered that this reaction at the interface of the organic solution and 
the aqueous solution imparts a specificity to the reaction for the 6 and 
the 6' primary alcohol groups of sucrose. 
It should be understood that equivalent reactants such as diepoxides and 
halohydrocarbyloxiranes such as epichlorohydrin also react in the process 
to provide new and useful sucrose ethers. 
It is a feature of the invention that the reaction can be controlled to 
produce at least four different types of compounds: a water-insoluble 
polymer, a water-soluble polymer, a sucrose dimer and a cyclic sucrose 
adduct. The relative amounts of each of these compounds can be selected by 
adjusting the conditions of the reaction. By the use of selected reaction 
conditions, yields of up to 95 to 100% of the desired product may be 
obtained. By appropriate selection of the type of acidic reactant, 
different structural groups with various chemical properties can be 
incorporated into the resulting sucrose compounds. 
These sucrose reaction products have a wide range of potential uses as food 
bulking agents, reduced calorie sweeteners, fat replacement agents for 
food products, stabilizing agents for food and beverage products, 
thickening and emulsifying agents for food products, adhesives, paper and 
textile sizing, biodegradable plastics and films, ethical pharmaceuticals, 
and new fibers. When applied in these areas, the sucrose reaction products 
are combined with a non-reactive carrier in amounts of about 1 wt. % up to 
99 wt. %.

EXAMPLE 1 
Synthesis of SP1, SP2 and SP4 (S=succinyl). 
Sucrose (200 g was dissolved in 100ml of 0.1M sodium hydroxide to give a 
5.85M solution. Sufficient succinic acid dichloride was dissolved in 250 
mL carbon tetrachloride to give a molar ratio of acid dichloride to 
sucrose of 1.2:1.0. The acid dichloride/carbon tetrachloride solution was 
added dropwise to the alkaline sucrose solution over 30 minutes with 
stirring at 22.degree. C. The pH of the sucrose solution was maintained 
between 7 and 9 by the addition of 10% (w/v) sodium hydroxide. When all 
the carbon tetrachloride solution had been added, the reaction was stirred 
for an additional 15 minutes and 2 volumes of water were then added. The 
carbon tetrachloride layer was removed and the insoluble material (SP1) 
was filtered off. Ethanol (1-1.5 volumes) was added to the aqueous 
solution, giving a precipitate (SP2) that was removed by filtration. The 
remaining aqueous ethanol solution was rotary evaporated to a syrup, 
giving product SP4. Each of the products was triturated with anhydrous 
acetone 3 to 4 times and then with ethanol to give a free-flowing solid. 
EXAMPLE 2 
Synthesis of SP4 (S=succinyl). 
Synthesis of 95 to 100% SP4 was accomplished by the reaction and procedures 
of Example 1 with the exceptions that the concentration of the acid 
chloride in the carbon tetrachloride was reduced to one-half by doubling 
the volume of carbon tetrachloride (to 500 mL in the above example), the 
reaction was conducted at 15.degree. C. instead of 22.degree. C., and the 
time of addition was increased to 60 minutes. The pH was maintained 
between 7 and 9. After addition was complete, the reaction mixture was 
stirred for an additional 30 minutes. Then two volumes of water were 
added, the carbon tetrachloride was removed, and the aqueous solution was 
rotary evaporated to a syrup. The syrup was triturated with acetone and 
ethanol as in Example 1, to obtain a solid or it was allowed to stand at 
room temperature for one to two weeks, whereupon crystallization occurred. 
EXAMPLE 3 
Synthesis of SP3 (S=succinyl). 
To produce 95% SP3, sucrose (200 g was dissolved in 100 mL of 0.1M sodium 
hydroxide. Sufficient succinyl dichloride was dissolved in 125 mL carbon 
tetrachloride to give a molar acid dichloride to sucrose ratio of 1:2. The 
carbon tetrachloride solution was added dropwise to the sucrose solution 
at 40.degree. C. over a period of 30 minutes. The pH was maintained 
between 7 and 9. When the reaction was complete, as judged by the end of 
acid formation, two volumes of water were added, the carbon tetrachloride 
was removed, and the aqueous solution was rotary evaporated to a syrup. 
The syrup was triturated with acetone and ethanol as described in the 
above examples. 
EXAMPLE 4 
Synthesis of P4 by the reaction with oxalyl dichloride (OP4 where 
O=oxalyl). 
The reaction conditions were essentially the same as for SP4 described 
above (Example 2) with the exception that the sucrose solution was kept at 
5.degree. C. during the addition of the oxalyl dichloride/carbon 
tetrachloride solution over a period of 30 minutes. After all the carbon 
tetrachloride solution had been added, the reaction mixture was allowed to 
warm to 15.degree. C. and stirred at this temperature for 15 minutes. It 
was thereafter allowed to warm to 22.degree. C. for an additional 15 
minutes. The work-up of product OP4 was the same as described in Example 
2. 
EXAMPLE 5 
Synthesis of P4 by the reaction with phosphorus oxychloride or diphosphoryl 
tetrachloride (PhP4 and Pyph P4 where Ph=phosphorous and 
Pyph=diphosphoryl). 
The reaction conditions were the same as for OP4 described above with the 
exception that the phosphorus oxychloride or diphosphoryl tetrachloride 
solution was added to the sucrose solution at 5.degree. C. over a period 
of 60 minutes. The work-up of products PhP4 and PyphP4 was the same as 
described for OP4 above. In the syntheses of Example 5, the pH was 
maintained between 7 and 9 by the addition of aqueous sodium hydroxide. 
The reaction was allowed to proceed until no more acid was formed. Before 
product work-up, the pH was adjusted to 7.0. 
In most syntheses, carbon tetrachloride was used as the water-immiscible 
organic solvent, but toluene or other solvents as described could be 
substituted with similar results. 
EXAMPLE 6 
Four different basic kinds of products can, thus, be obtained (P1, P2, P3, 
and P4). In addition, each of the four products can be made from different 
acid chlorides (epoxides), each giving different chemical properties to 
the four products, depending on the particular acid chloride (epoxide). 
The number of possible products, thus, would be 4.times.n, where n is the 
number of types of acid chlorides (epoxides). For example, if eight 
different acid chlorides were used, there would be a total of 32 different 
kinds of possible esters. As examples, some of the different kinds of 
products can be differentiated in the following way: 
OP1, OP2, OP3, OP4 where O is oxalyl 
SP1, SP2, SP3, SP4 where S is succinyl 
AP1, AP2, AP3, AP4 where A is adipoyl 
MP1, MP2, MP3, MP4 where M is malonyl 
FP1, FP2, FP3, FP4 where F is fumaryl 
PP1, PP2, PP3, PP4 where P is phthaloyl 
PhP1, PhP2, PhP3, PhP4 where Ph is phosphoryl 
PyphP1, PyphP2, PyphP3, PyphP4 where Pyph is pyrophosphoryl, 
EpiP1, EpiP2, EpiP3, EpiP4 when Epi is 2-hydroxy-1,3-propandiyl, 
where again P1, P2, P3, P4 represents the four types of general products 
that can be formed. 
EXAMPLE 7 
Synthesis of Cyclic 6,6'-(2-hydroxy-1,3-propandiyl) Sucrose by Reaction 
with Epichlorohydrin. 
Sucrose (20 g, 58.4 mmol) was dissolved in 10 mL of 0.1 M NaOH. 
Epichlorohydrin (6.5 g, 70 mmol) was dissolved in 50 mL of toluene and 
added dropwise to the sucrose solution at room temperature over 30 min 
with constant stirring. The pH of the reaction mixture was maintained 
between 8-10 by the addition of 20% (w/v) NaOH. After all of the 
epichlorohydrin solution had been added, the reaction mixture was allowed 
to stir for another 30 min. The two phases were then separated. The 
aqueous phase was neutralized to pH 7 and then rotoevaporated to a syrup, 
with salts separating out. The syrup was allowed to stand at room 
temperature for 3-4 days when crystalline needles appeared and increased 
over the next several days. 
The cyclic products P4 of Example 7 can be prepared using a reactant such 
as epichlorhydrin or a bifunctional acidic reactant as described herein 
(Examples 2 and 4-6). These reactants and the resulting products are 
illustrated in the following structural formula: 
##STR4## 
The invention has been described herein with reference to certain preferred 
embodiments. However, as obvious variations thereon will become evident to 
those skilled in the art, the invention is not to be considered as limited 
thereto.