(c)The pyranose form of D-xylose is just like that of D-glucose except that it lacks a CH2OHgroup.We would expect the equilibrium between pyranose forms in D-xylose to be much like that inD-glucose and predict that the -pyranose form would predominate. It is observed that theratio in D-xylose is 64 : 36, exactly the same as in D-glucose.(d)The pyranose form of D-lyxose is like that of D-mannose except that it lacks a CH2OH group.As in D-mannopyranose, the form should predominate over the .The observed distribution ratio in D-lyxopyranose is 73 : 27.25.30(a)The rate-determining step in glycoside hydrolysis is carbocation formation at the anomericposition. The carbocation formed from methyl -D-fructofuranoside (compound A) is tertiary
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