Table 1. NMR spectroscopic data (δ from TMS, multiplicity) for compounds 1, 2 and 3.

1
(CDCl₃/0.1%DMSO-d₆)

2
(MeOD-d₄)

3
(DMSO-d₆)

Position

δ_H

δ_C

δ_H

δ_C

δ_H

δ_C

1

7.07, d
(J= 2Hz)

108.56

6.95, d
(J= 2.1Hz)

109.02

6.97, d
(J= 2.1Hz)

109.09

2

128.69

130.10

130.10

3

6.65, d
(J= 2Hz)

103.65

6.65, d
(J= 2.1Hz)

104.46

6.67, d
(J= 2.1Hz)

104.46

4

157.16

159.37

158.86

5

158.86

6.12, s

108.95

149.41

6

112.94

112.80

112.80

7

142.05

149.41

6.23, s

109.78

8

155.08

160.70

160.07

9

110.67

111.00

112.00

10

125.58

127.85

127.85

CH₃-6

2.64, s

18.96

2.19, s

22.18

2.29, s

21.18

OCH₃-2

3.72, s

52.23

3.70, s

52.62

3.70, s

52.71

OCH₃-4

3.70, s

56.13

3.66, s

56.70

3.68, s

56.70

CO-2

166.17

163.44

168.06

CO-6

200.31

202.31

202.31

OH-5, 7, 8

10.8 (2H) and
9.51 (1H), br s