The present invention relates to a method for preparing an at least partially acetal-protected sugar involving the step of reacting a sugar or a sugar derivative selected from the group consisting of an aldopentose, an aldohexose, an aldopentoside and an aldohexoside with an aldehyde or an aldehyde source in the presence of heterogeneous acidic catalyst to form the at least partially acetal-protected sugar selected from the group consisting of a compound of formula (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X,)(XI) and (XII) wherein R.sub.1, R.sub.1, R.sub.2, R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, and R.sub.12 are Y or Z-E, and wherein R.sub.1 and R.sub.1, R.sub.2 and R.sub.2, R.sub.3 and R.sub.3, and R.sub.12 and R.sub.12 are the same or different from each other and Y is hydrogen or a linear, branched or cyclic hydrocarbon moiety having 1 to 20 carbon 69 atoms, Z is a linear, branched or cyclic hydrocarbon moiety with 0 to 12 carbon atoms, optionally substituted with 1 to 4 C1 to C4 alkyl groups, 1 to 4 halogen atoms, or benzyl groups and E is COOH, CH(COOH).sub.2, COOR.sub.19, CH(COOR.sub.20)(COOR.sub.21), CHO, CH(CHO).sub.2, C.sub.2H.sub.3, CH(C.sub.2H.sub.3).sub.2, CHCHR.sub.22, CHCR.sub.23R.sub.24, C.sub.2H, C.sub.2R.sub.25, N.sub.3, NH.sub.2, CH(NH.sub.2).sub.2, NHR.sub.26, CH(NHR.sub.27)(NHR.sub.28), NR.sub.29R.sub.30, CH(NR.sub.31R.sub.32)(NR.sub.33R.sub.34), OH, OR.sub.35, CH(R.sub.36OH)(R.sub.37OH), and R.sub.19, R.sub.20, R.sub.21, R.sub.22, R.sub.23, R.sub.24, R.sub.25, R.sub.26, R.sub.27, R.sub.28, R.sub.29, R.sub.30, R.sub.31, R.sub.32, R.sub.33, R.sub.34, and R.sub.35, are independent from each other C.sub.1 to C.sub.20 alkyl, and R.sub.20 and R.sub.21, R.sub.23 and R.sub.24, R.sub.27 and R.sub.28, R.sub.29 and R.sub.30, R.sub.31 and R.sub.32, as well as R.sub.33 and R.sub.34 are the same or different from each other, and R.sub.36 and R.sub.37 are independent from each other absent or a linear or branched C.sub.1 to C.sub.12 hydrocarbon chain and R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17 and R.sub.18 are independent from each other hydrogen or a linear, branched or cyclic hydrocarbon moiety having 1 to 20 carbon atoms.

The present invention relates to a method for preparing an at least partially acetal-protected sugar involving the step of reacting a sugar or a sugar derivative selected from the group consisting of an aldopentose, an aldohexose, an aldopentoside and an aldohexoside with an aldehyde or an aldehyde source in the presence of heterogeneous acidic catalyst to form the at least partially acetal-protected sugar selected from the group consisting of a compound of formula (I), (II), (III), (IV), (V), (VI), (VII), (VIII), (IX), (X,)(XI) and (XII) wherein R.sub.1, R.sub.1, R.sub.2, R.sub.2, R.sub.3, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10, R.sub.11, R.sub.12, and R.sub.12 are Y or Z-E, and wherein R.sub.1 and R.sub.1, R.sub.2 and R.sub.2, R.sub.3 and R.sub.3, and R.sub.12 and R.sub.12 are the same or different from each other and Y is hydrogen or a linear, branched or cyclic hydrocarbon moiety having 1 to 20 carbon 69 atoms, Z is a linear, branched or cyclic hydrocarbon moiety with 0 to 12 carbon atoms, optionally substituted with 1 to 4 C1 to C4 alkyl groups, 1 to 4 halogen atoms, or benzyl groups and E is COOH, CH(COOH).sub.2, COOR.sub.19, CH(COOR.sub.20)(COOR.sub.21), CHO, CH(CHO).sub.2, C.sub.2H.sub.3, CH(C.sub.2H.sub.3).sub.2, CHCHR.sub.22, CHCR.sub.23R.sub.24, C.sub.2H, C.sub.2R.sub.25, N.sub.3, NH.sub.2, CH(NH.sub.2).sub.2, NHR.sub.26, CH(NHR.sub.27)(NHR.sub.28), NR.sub.29R.sub.30, CH(NR.sub.31R.sub.32)(NR.sub.33R.sub.34), OH, OR.sub.35, CH(R.sub.36OH)(R.sub.37OH), and R.sub.19, R.sub.20, R.sub.21, R.sub.22, R.sub.23, R.sub.24, R.sub.25, R.sub.26, R.sub.27, R.sub.28, R.sub.29, R.sub.30, R.sub.31, R.sub.32, R.sub.33, R.sub.34, and R.sub.35, are independent from each other C.sub.1 to C.sub.20 alkyl, and R.sub.20 and R.sub.21, R.sub.23 and R.sub.24, R.sub.27 and R.sub.28, R.sub.29 and R.sub.30, R.sub.31 and R.sub.32, as well as R.sub.33 and R.sub.34 are the same or different from each other, and R.sub.36 and R.sub.37 are independent from each other absent or a linear or branched C.sub.1 to C.sub.12 hydrocarbon chain and R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.17 and R.sub.18 are independent from each other hydrogen or a linear, branched or cyclic hydrocarbon moiety having 1 to 20 carbon atoms.

Compounds and compositions that have an asialoglycoprotein receptor (ASGPR) binding ligand bound to an extracellular protein binding ligand for the selective degradation of the target extracellular protein in vivo to treat disorders mediated by the extracellular protein are described.

Compounds and compositions that have an asialoglycoprotein receptor (ASGPR) binding ligand bound to an extracellular protein binding ligand for the selective degradation of the target extracellular protein in vivo to treat disorders mediated by the extracellular protein are described.