Synthesis, intramolecular migrations and enzymic hydrolysis of partially pivaloylated methyl alpha-D-mannopyranosides.
A series of methyl O-pivaloyl-alpha-D-mannopyranosides was synthesized using pivaloyl chloride in pyridine. The 3,6-di-O-pivaloyl derivative 6 undergoes intramolecular transesterification in neutral conditions (buffer, pH 7.2) to give its 2,6-di-O-pivaloyl analogue 5. The course of this migration was followed using 14C-labelled 6. As opposed to 6 compound 5 was shown to be a good substrate for esterases present in rabbit serum. Thus, regioselective enzymic hydrolysis led to the preferential cleavage of the 2-OPiv group to yield a mixture of 2- and 6-O-monopivalates in a ratio of 1:2.6.
Tomić
Srdanka
S
Department of Chemistry, Faculty of Science, University of Zagreb, Strossmayerov trg 14, HR-10000, Zagreb, Croatia. srdjanka@rudjer.irb.hr <srdjanka@rudjer.irb.hr>
Petrović
Vesna
V
Matanović
Maja
M
D000818:Animals; D002236:Carbohydrate Conformation; D004950:Esterases / Q000378:metabolism; D004951:Esterification; D006868:Hydrolysis; D008766:Methylmannosides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D015394:Molecular Structure; D009038:Motion; D010421:Pentanoic Acids / Q000737:chemistry*; D011817:Rabbits
D008766:Methylmannosides; D010421:Pentanoic Acids; C059099:pivaloyl chloride; C008466:methylmannoside; D004950:Esterases