Abstract: The compounds 2-(5-methylthiomethyl-2-furyl)-2-hydroxy-3-keto-4- dihydroxyethylbutyrolactone and 2-(5-methoxymethyl-2- furyl)-2-furyl(-2-hydroxy-3-keto-4-dihydroxyethylbutyrolactone and pharmaceutical compositions containing them are useful to regulate the immune response in mammals.

Abstract: Michael addition products of ascorbic acid and selected unsaturated aldehydes and ketones are useful as immunomodulators in mammals.

Abstract: It has now been discovered that the acid catalyzed Michael reaction products of ascorbic acid and certain selected ketones are useful for their therapeutic activity. More specifically the useful reaction products of the invention are those obtained by reactions of ascorbic acid with .alpha.,.beta. unsaturated alicyclic diketones containing from 5 to 7 carbon atoms.The preferred compounds of the invention may be represented by the formula: ##STR1## wherein n is 1, 2 or 3. The ability of the compounds of this invention to stimulate an immune response has been established by a number of art recognized tests.

Abstract: Novel 2-furylbutyrolactones are directly formed by reaction of 2,5-dialkoxy-2,5-dihydrofurans and 2,3-dihydroxybutenolides in aqueous media and recovering crystalline product from an anhydrous medium. These novel compounds and compositions containing same may be used for lymophocyte stimulation.

Abstract: Novel cyclic acetals of the general formulae: ##STR1## wherein R.sub.1 is ##STR2## wherein R.sub.2 is hydrogen, alkyl, aryl or R.sub.1, wherein R.sub.3 through R.sub.10 are hydrogen, alkyl or aryl, wherein R.sub.5 and R.sub.6 together may form .dbd.O, wherein X is hydrogen, alkyl, cycloalkyl, aryl, hydroxyaryl or arylakyl, or wherein R.sub.8 is ##STR3## are described. Said compounds are prepared by mixing approximately equimolar amounts of the appropriate aldehyde or ketone, and enediol compound, and allowing same to react in aqueous solution under a nitrogen atmosphere.Compositions containing these novel compounds exhibit hypotensive and analgesic properties and are useful in the treatment of hypertension and pain in animals and humans.

Abstract: Novel chemical compounds of the general formulae: ##STR1## wherein R.sub.1 and R.sub.2 are hydrogen, alkyl, cycloalkyl, aryl or arylalkyl, wherein R.sub.3 through R.sub.10 are hydrogen, alkyl, or aryl, wherein R.sub.5 and R.sub.6 together may form .dbd.0, and wherein X is hydroxy. The compounds are prepared by mixing specified amounts of a dialdehyde, .alpha.-keto-aldehyde, or diketone, such as methylglyoxal or a related compound, and an enediol, such as L-ascorbic acid or a compound that can be converted into an enediol, such as an acyloin, and allowing same to react under a nitrogen atmosphere in the presence of a non-interfering solvent.Compositions containing these novel compounds exhibit cytostatic, hypotensive and analgesic properties and are useful in the treatment of cancer in animals and humans.