The invention is directed to the field of pro-fragrances used in detergents and cleaning agents, cosmetic agents and air fresheners, for example. The invention relates to particular cyclic ketals used as pro-fragrances. The invention also relates to detergents and cleaning agents, cosmetic agents and air fresheners containing ketals of the type. The invention further relates to a method for creating a long-lasting fragrance on surfaces and for repelling insects.

In accordance with the present subject matter there is provided sugar-based compounds of formula I, methods of making such compounds, gels comprising such compounds, methods of making gels, methods of using such compounds for the containing spill of a hydrocarbon, and methods for reclaiming solvent from gels comprising such compounds. ##STR00001##

In accordance with the present subject matter there is provided sugar-based compounds of formula I, methods of making such compounds, gels comprising such compounds, methods of making gels, methods of using such compounds for the containing spill of a hydrocarbon, and methods for reclaiming solvent from gels comprising such compounds. ##STR00001##

The invention relates to a method for the preparation of a 4,5-dihydroxyisoleucine derivative comprising the steps of asymmetric Claisen rearrangement of a Z-aminocrotyl-glycin ester and subsequent kinetic resolution of the product diastereomer mix by acylase, and subsequent Sharpless dihydroxylation of the resulting 2-amino-3-methylpent-4-enoic acid derivative.

A hydrophilic polymer derivative having a cyclic benzylidene acetal linker represented by the following formula (1):

##STR00001##

wherein R.sup.1 and R.sup.6 are each independently a hydrogen atom or a hydrocarbon group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently an electron-withdrawing or electron-donating substituent or a hydrogen atom; X.sup.1 is a chemically reactive functional group; P is a hydrophilic polymer; s is 1 or 2, t is 0 or 1, and s+t is 1 or 2; w is an integer of 1 to 8; and Z.sup.1 and Z.sup.2 are each independently a selected divalent spacer.

A hydrophilic polymer derivative having a cyclic benzylidene acetal linker represented by the following formula (1):

##STR00001##

wherein R.sup.1 and R.sup.6 are each independently a hydrogen atom or a hydrocarbon group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently an electron-withdrawing or electron-donating substituent or a hydrogen atom; X.sup.1 is a chemically reactive functional group; P is a hydrophilic polymer; s is 1 or 2, t is 0 or 1, and s+t is 1 or 2; w is an integer of 1 to 8; and Z.sup.1 and Z.sup.2 are each independently a selected divalent spacer.

A lipid derivative in which a hydrophilic polymer is bound through a cyclic benzylidene acetal linker, and which can accurately control a hydrolysis rate in the weakly acidic environment of a living body to detach the hydrophilic polymer from a lipid membrane structure. The lipid derivative is represented by formula (1): ##STR00001##
wherein, R.sup.1 and R.sup.6 are each independently a hydrogen atom or a hydrocarbon group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently an electron-withdrawing or electron-donating substituent or a hydrogen atom; R.sup.7 is a hydrocarbon group having from 8 to 24 carbon atoms, an acyl group having from 8 to 24 carbon atoms, a cholesterol derivative, a glycerolipid, a phospholipid or a sphingolipid; P is a hydrophilic polymer; s is 1 or 2, t is 0 or 1, and s+t is 1 or 2; and Z.sup.1 and Z.sup.2 are each independently a selected divalent spacer.

A lipid derivative in which a hydrophilic polymer is bound through a cyclic benzylidene acetal linker, and which can accurately control a hydrolysis rate in the weakly acidic environment of a living body to detach the hydrophilic polymer from a lipid membrane structure. The lipid derivative is represented by formula (1): ##STR00001##
wherein, R.sup.1 and R.sup.6 are each independently a hydrogen atom or a hydrocarbon group; R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each independently an electron-withdrawing or electron-donating substituent or a hydrogen atom; R.sup.7 is a hydrocarbon group having from 8 to 24 carbon atoms, an acyl group having from 8 to 24 carbon atoms, a cholesterol derivative, a glycerolipid, a phospholipid or a sphingolipid; P is a hydrophilic polymer; s is 1 or 2, t is 0 or 1, and s+t is 1 or 2; and Z.sup.1 and Z.sup.2 are each independently a selected divalent spacer.

Provided herein are prodrug compounds, their preparation and their uses, such as treating liver diseases or nonliver diseases via intervening in molecular pathways in the liver.

In one aspect, the present disclosure provides methods of preparing a primary or secondary amine and hydroxylated aromatic compounds. In some embodiments, the aromatic compound may be unsubstituted, substituted, or contain one or more heteroatoms within the rings of the aromatic compound. The methods described herein may be carried out without the need for transition metal catalysts or harsh reaction conditions.