Preparation of ethers of monosaccharides

Abstract

Ethereally substituted monosaccharides are prepared from certain selectively derivatized monosaccharides. In practicing the method: 1. a monosaccharide derivative having the general formula A.sub.1 -O-H, wherein O is oxygen, H is hydrogen and A.sub.1 is the residue of a monosaccharide selected from the group consisting of pentoses, hexoses and heptoses which has been derivatized with at least one substance selected from the group consisting of (1-a) at least one aliphatic alcohol containing 1-18 carbon atoms to produce an hydrolyzable acetal group at the site of at least one available hydroxyl residue, (1-b) at least one aldehyde containing 1-18 carbon atoms to produce at least one hydrolyzable acetal group at the site of at least one available hydroxyl residue, (1-c) at least one ketone containing 1-18 carbon atoms to produce at least one hydrolyzable ketal group at the site of at least one available hydroxyl residue, and (1-d) at least one organic acid residue containing 1-18 carbon atoms to produce an hydrolyzable ester group at the site of at least one available hydroxyl residue; is reacted with 2. an organic halide having the general formula Y - X, wherein X is selected from the group consisting of chlorine, bromine and iodine and Y is selected from the group consisting of (2-a) cyclic monovalent nitrogen containing organic radicals and residua, and (2-b) monovalent organic radicals and residue having the general formula -R.sub.1 B wherein B is selected from the group consisting of ##STR1## --O--R.sub.4 and --S--R.sub.4, R.sub.1 is a divalent organic radical having a linear carbon chain length of about 1-7 carbon atoms, R.sub.2 and R.sub.3 are selected from the group consisting of --H,--OH, --SH, halogen and monovalent organic radicals and residua having a linear carbon chain length of about 1-7 carbon atoms, R.sub.4 is selected from the group consisting of --H and monovalent organic radicals and residua having a linear carbon chain length of about 1-7 carbon atoms, N is nitrogen, O is oxygen, S is sulfur and H is hydrogen; To produce an ethereally substituted monosaccharide derivative having the general formula A-O-Y wherein A, Y and O are as above defined. The monosaccharide derivative (1) and the organic halide (2) are reacted at an elevated reaction temperature while dissolved in a substantially anhydrous organic solvent in the presence of a solid substantially anhydrous strong inorganic base of a metal selected from the group consisting of the alkali metals and the alkaline earth metals. The resultant ethereally substituted monosaccharides may be partially or fully hydrolyzed in an aqueous acidic medium. In one preferred variant, 1,2:5,6-di-O-isopropylidene 3-O-3'-(N',N'-dimethylamino-n-propyl)-D-glucofuranose is prepared and, when desired, thereafter partially or fully hydrolyzed to produce 1,2-O-isopropylidene-3-O-3'-(N',N'-dimethylamino-n-propyl)-D-glucofuranose or 3-O-3'-(N'-N'-dimethylamino-n-propyl-D-glucose in the free amine and/or salt forms. The method is capable of preparing the ethereally substituted monosaccharides in high yield and purity with a minimum of side products. The resultant compounds exhibit striking antiviral activity and/or have other therapeutically valuable properties and are useful in the treatment of warm-blooded animals.