the use of donkey , pig , horse , sheep and human serum led to the migration of the 2-o-pivaloyl group in substrate 1 to the position 4- in the sugar molecule , followed by stepwise de-esterifications of both 1 and the newly formed methyl 4,6-di-o-pivaloyl-alpha-d-glucopyranoside ( 4 ) .
C0086418
human
C3538902
di