TRI-O-BENZOYL-BETA-L-RHAMNOPYRANOSYL AND BETA-L-FUCOPYRANOSYL ISOTHIOCYANATES - PARTIALLY PROTECTED BETA-L-RHAMNOPYRANOSYLENAMINES

Regioselective benzoylations of diethoxycarbonylvinyl)-beta-L-rhamnopy ranosylamine (1) yielded 2,3-di-O- (3), 3,4-di-O- (4), and diethoxycar bonylvinyl)-beta-L-rhamnopyranosylamine (5) together with the tri-O-be nzoylated derivative 2. Syntheses of 2,3,4-tri-O-benzoyl-beta-L-rhamno - (7) and -beta-L-fuco-pyranosyl isothiocyanate (13) from 2 and L-fuco pyranosylamine, respectively, are described. N-Phenacyl-N'-(2,3,4-tri- O-benzoyl-beta-L-rhamno- (8) and -beta-L-fuco-pyranosylthiourea (14) w ere prepared from 7 and 13, respectively, by reaction with phenacylami ne. Conformational properties and MS data of the prepared compounds ar e discussed.