Compound

R

Initial aldose

Form in crystals

Tautomeric composition (%) in D₂O

Form B

Form A

Form C

2a

H

L-Arabinose

D

10

-

90

2b

H

D-Xylose

D

25

-

75

2c

CH₃

L-Rhamnose

B

100

-

-

2d

CH₂OH

D-Galactose

D

15

-

85

2e

CH₂OH

D-Glucose

B

70

-

30

2f

CH₂OH

D-Mannose

D

10

-

90