Compound

X

R

Initial aldose

Form in crystals

Tautomeric composition (%) in DMSOd₆

Form B

Form A

Form C

1a

O

H

L-Arabinose

B

45

30

25

1b

O

H

D-Ribose

B

50

40

10

1c

O

CH₃

L-Rhamnose

B

80

20

-

1d

O

CH₂OH

D-Galactose

B

70

30

-

1e

O

CH₂OH

D-Glucose

B

95

5

-

1f

O

CH₂OH

D-Mannose

B

35

65

-

1g

NH

H

L-Arabinose

B

65

25

10

1h

NH

H

D-Ribose

A

25

60

15

1i

NH

CH₂OH

D-Glucose

B

100

-

-

1j

NH

CH₂OH

D-Mannose

B

100

-

-