Glycoside preparation directly from aqueous saccharide solutions or syrups

Claim 2

A process for preparing a glycoside product by reacting a water soluble monosaccharide reactant with a C 2 to C 6 monohydric aliphatic alcohol reactant, which process comprises: a. admixing an aqueous solution containing, on a total aqueous solution weight basis, from about 20 to about 90 weight percent of said monosaccharide reactant with the alcohol reactant to provide a homogeneous, single phase aqueous reaction medium which comprises said monosaccharide and alcohol reactants and water and which is free of any separate and distinct aqueous phase consisting essentially of only water and the monosaccharide reactant; and b. reacting said monosaccharide reactant with said alcohol reactant by contacting said homogeneous aqueous reaction medium with an acid catalyst at a temperature of from about 60° to about 200° C. while removing water from the reaction mixture at a rate sufficient to prevent the formation of a separate and distinct aqueous monosaccharide solution phase during the course of said reaction.

Claim 3

the process of claim 1 wherein the alcohol reactant is a monohydric alkanol containing from 2 to 6 carbon atoms.

Claim 4

The process of claim 2 wherein the alcohol reactant is a monohydric alkanol containing from 2 to 4 carbon atoms.

Claim 5

The process of claim 1 wherein the aqueous solution of monosaccharide reactant is an aqueous glucose syrup.

Claim 6

The process of claim 4 wherein the glucose syrup contains from about 50 to about 80 weight percent glucose solids on a total syrup weight basis.

Claim 7

The process of claim 1 wherein the acid catalyst is a water soluble acid material.

Claim 8

The process of claim 6 wherein the acid catalyst is p-toluene sulfonic acid.

Claim 9

The process of claim 1 wherein the acid catalyst is a strongly acidic, solid material which is insoluble in water and in the alcohol reactant employed.

Claim 10

The process of claim 1 wherein the acid catalyst is an acidic ion exchange resin.

Claim 11

The process of claim 9 wherein the acid catalyst is a macroreticular sulfonic acid ion exchange resin.

Claim 12

The process of claim 1 wherein the reaction between said alcohol reactant and the monosaccharide reactant is conducted at a temperature of from about 80° to about 150° C.

Claim 13

The process of claim 1 wherein the alcohol reactant is selected from the group consisting of isopropanol, n-propanol, n-butanol and allyl alcohol.

Claim 14

The process of claim 1 wherein the homogeneous aqueous reaction medium is substantially saturated with the aqueous monosaccharide solution at the time that said reaction medium is contacted with said acid catalyst.

Claim 15

The process of claim 13 wherein the substantially saturated homogeneous aqueous reaction medium is obtained as a result of a countercurrent two phase liquid/liquid mass transfer process in which a dispersed discrete aqueous monosaccharide solution phase is contacted with a continuous phase of said alcohol reactant in a ratio such that the quantity of aqueous monosaccharide solution phase is in excess of that which the alcohol reactant phase is capable of dissolving and wherein the remaining, undissolved aqueous monosaccharide solution phase is separated from the resulting substantially saturated homogeneous aqueous alcohol monosaccharide reaction medium prior to contacting said reaction medium with the acid catalyst.

Claim 16

The process of claim 14 wherein the acid catalyst is a water and alcohol insoluble acidic ion exchange resin in the form of a fixed ion exchange resin bed or column through which the homogeneous aqueous alcohol monosaccharide reaction medium is passed in order to accomplish the desired alcohol monosaccharide reaction.

Claim 17

The process of claim 1 wherein the acid catalyst is a water and alcohol insoluble acidic ion exchange resin in the form of fixed ion exchange resin bed or column through which the homogeneous, aqueous alcohol/monosaccharide reaction medium is passed in order to accomplish the desired alcohol monosaccharide reaction.

Claim 18

The process of claim 1 wherein the aqueous monosaccharide solution contains, on a total aqueous solution weight basis, from about 50 to about 80 weight percent of the monosaccharide reactant.

Claim 19

The process of claim 1 wherein the alcohol reactant further comprises at least a small quantity of methanol.

Claim 20

A process for preparing glycosdes directly from an aqueous monosaccharide solution, said process comprising; a. admixing an aqueous solution containing, on a total aqueous solution weight basis, from about 20 to about 90 weight percent of a water soluble monosaccharide reactant with a sufficient amount of a C 2 to C 6 monohydric aliphatic alcohol reactant to completely dissolve said aqueous monosaccharide solution and to thereby provide a homogeneous, aqueous, single phase reaction medium comprising said monosaccharide and alcohol reactants and water; and b. contacting said homogeneous aqueous reaction medium with an acid catalyst at a temperature of from about 60° to about 200° C. to thereby cause a condensation reaction to occur between said monosaccharide and alcohol reactants to form the desired glycoside reaction product, while simultaneously removing water generated by said condensation reaction from said aqueous reaction medium at a rate sufficient to prevent the formation of a separate and distinct aqueous phase consisting essentially of only water and the monosaccharide reactant within said aqueous reaction medium.

Claim 21

A process for preparing glycosdes directly from an aqueous monosaccharide solution, said process comprising; a. admixing an aqueous solution containing, on a total aqueous solution weight basis, from about 20 to about 90 weight percent of a water soluble monosaccharide reactant with a sufficient amount of a C 2 to C 6 monohydric aliphatic alcohol reactant to completely dissolve said aqueous monosaccharide solution and to thereby provide a homogeneous, aqueous, single phase reaction medium comprising said monosaccharide and alcohol reactants and water; and b. contacting said homogeneous aqueous reaction medium with an acid catalyst at a temperature of from about 60° to about 200° C. to thereby cause a condensation reaction to occur between said monosaccharide and alcohol reactants to form the desired glycoside reaction product, while simultaneously removing water generated by said condensation reaction from said aqueous reaction medium at a rate sufficient to prevent the formation of a separate and distinct aqueous phase consisting essentially of only water and the monosaccharide reactant within said aqueous reaction medium.