Patent ID: 6953850

Claim:
An orthogonally protected monosaccharide building block of Formula I or Formula II in which A is a leaving group selected from the group consisting of halogen, trichloroacetimidoyl, sulphoxide, —O-alkenyl; and —SR, where R is alkyl, alkenyl, alkynyl, cycloalkyl or aryl. X 1 , X 2 , and X 3 are independently selected from H, O, N, or N 3 , with the proviso that only one of X 1 , X 2 , and X 3 is H, N or N 3 in any molecule; X 4 is —CH 2 O; and B, C, D and E are different and of them B, C, or D is absent if the corresponding X 1 to X 3 is H or N 3 , and B, C, D and/or E are selected from protecting groups which can be cleaved orthogonally in any order, such that the cleavage conditions do not compromise the stability of the other protecting or functional groups on the monosaccharide building block, wherein the protecting groups for hydroxy protection are selected from the group consisting of acyl-type protecting groups, carbonates, t-butyldiphenylsilyl, triisopropylsilyl, trimethylsilylethyl, triphenylsilylethyl, trifluoromethyl, trichloromethyloxymethyl, trichloromethyfoxycarbonate, ethoxyethyl, cyanoethyl, NSC (p-ntirobenzyl-sulphonylethyloxycarbonyl), p-nitrobenzyl-sulphonylethyl, naphthylmethyl, substituted naphthylmethyl, p-methoxybenzyl, 3,4-dimethoxybenzyl, 2,4,6-trimethoxybenzyl, 3,4-methylenedioxybenzyl, acylamidobenzyl, azidobenzyl, p-azido-m-chlorobenzyl, allylic protecting groups, o-nitrobenzyloxycarbonate, o-nitrobenzyl, dinitrobenzyl, 2-oxo-1,2-diphenylethyl, methylthioethyl, acyloxybenzyl and benzylthioethyl; and for amino protection are selected from the group consisting of Dde (N-[1-(4,4-dimethyl-2,6-dioxocyclohex-1-ylidene)ethyl]), Wow ((1,3-dimethyl-2,4,6-(1H,3H,5H)-trioxopyrimidin-5-ylidene) methyl), tetraphthaloyl, dichlorophthaloyl, 2,5-dimethyl-pyrrol benzyloxycarbonyl, and pentenyl.