Table 2.

¹³C NMR Data of 4A-Ketopremithramycin A2 (11), 4A-Keto-9-demethylpremithramycin A2 (12), 4C-Keto-demycarosylmithramycin (13), and 4E-Ketomithramycin (14) in Acetone-d₆ at 125.7 MHz (δ in ppm Relative to Internal TMS, Assignments Were Made with the Help of Couplings Determined in the HSQC and HMBC Spectra)^a

	δ					δ
	11	12	13	14		11	12	13	14
1	196.1	n.o.	203.7	204.0	1A	97.9	97.9	96.8	96.9
2	112.6	112.6	77.6	76.8	2A	36.9	36.9	37.2	37.5
3	193.1	n.o.	42.4	42.8	3A	82.0	82.1	80.4	81.4
4	77.6	77.6	27.1	27.3	4A	90.6	91.0	75.2	75.4
4-OCH3	61.2	61.2			5A	70.5	70.5	72.3	72.6
4a	42.7	42.5	136.4	136.5	6A	12.7	12.7	17.9	17.9
5	26.5	27.0	101.7	101.7	1B	100.5	100.5	99.4	100.0
5a	134.3	133.0			2B	34.8	34.8	39.7	40.0
6	117.6	117.8	159.6	159.2	3B	68.8	68.9	70.9	71.3
7	102.3	103.0	111.1	111.1	4B	70.3	70.6	77.0	77.5
7-CH3			7.97	7.9	5B	71.5	71.5	72.6	72.6
8	161.7	163.0	155.7	156.2	6B	16.4	16.7	17.6	16.5
8a			107.8	108.4	1C			101.3	100.9
9	110.4	102.0	164.0	165.3	2C			36.3	38.0
9a			108.7	108.6	3C			81.4	81.8
9-CH3	7.7				4C			91.3	75.7
10	157.1	160.6	117.3	117.2	5C			73.8	72.6
10a	106.8	107.1	138.9	139.0	6C			12.7	17.6
1′	202.9	202.9	81.9	82.1	1D			100.1	100.4
1′-OCH3			58.7	58.8	2D			34.4	36.0
2′	27.9	27.3	212.1	211.3	3D			68.7	68.9
3′			79.1	79.2	4D			69.9	70.2
4′			68.3	68.4	5D			71.5	71.1
5′			19.3	19.6	6D			16.4	14.7
					1E				97.5
					2E				48.0
					3E				69.2
					3E-CH3				23.8
					4E				206.0
					5E				71.7
					6E				18.0

^an.o. = not observed.