119947-99-8 Mdmepo Methyl 3-deoxy-7,8 O-(1-methylethylidene)-1-O-(phenylmethyl)-alpha-D-manno-2-octalopyranoside Methyl 3-deoxy-7,8-O-(1-methylethylidene)-1-O-(phenylmethyl)-2-octalopyranoside cyclic carbonate