Table 1.

The ¹H and ¹³C NMR Spectral Data of 1–2.

Position	1		2
	δH (Mult, J in Hz) *	δC **	δH (Mult, J in Hz) *	δC **
1		169.2		167.2
3	6.36 (s, 1H)	103.2	10.33 (s, 1H)	196.6
3a		123.4		113.3
4		155.5		165.4
5	6.68 (d, J = 2.0 Hz, 1H)	109.6	6.96 (d, J = 2.4 Hz, 1H)	112.1
6		162.5		167.0
7	6.74 (d, J = 2.0 Hz, 1H)	103.1	6.52 (d, J = 2.4 Hz, 1H)	106.7
7a		131.3		137.8
8	3.49 (s, 3H)	56.2	3.93 (s, 3H)	53.4

* Recorded at 600 MHz in (CD₃)₂OD, λ in ppm; ** Recorded at 150 MHz in (CD₃)₂OD; λ in ppm.