Table 1.

Comparison of NMR data and optical rotation of isolated and synthesized compounds 4 and 27.

	Floyocidin‐B (isolated NP)		4 (synthetic)		27 (synthetic)
Position	1H‐NMR	13C‐NMR	1H‐NMR	13C‐NMR	1H‐NMR	13C‐NMR
	$\delta$ H (500 MHz)[a]	$\delta$ C (125 MHz)[a]	$\delta$ H (600 MHz)[a]	$\delta$ C (150 MHz)[a]	$\delta$ H (500 MHz)[a]	$\delta$ C (125 MHz)[a]
1a	3.82, d (1.9)	61.1	3.83, d (1.9)	61.1	3.82, d (2.3)	61.9
2	5.17, s, br	65.3	5.18, s, br	65.3	5.21, d (2.3)	64.9
2a		133.8		133.8		133.6
3	8.74, s	150.0	8.75, s	149.9	8.61, s	152.5
5		157.5		157.5		158.5
6	7.67, s	117.1	7.68, s	117.1	7.72, s	117.5
6a		137.7		137.7		138.2
7		195.4		195.4		195.5
7a		63.1		63.1		62.1
8	2.81, dd (15.2, 8.0)	27.2	2.82, dd (15.2, 8.0)	27.2	2.84, dd (15.2, 8.0)	27.5
	2.64, dd (15.2, 6.9)		2.65, dd (15.2, 6.9)		2.63, dd (15.2, 6.9)
9	5.14, m	117.8	5.14, m	117.8	5.15, m	117.8
10		137.0		137.0		137.0
11	1.69, s	18.1	1.70, s	18.1	1.69, s	18.1
12	1.73, s	26.0	1.74, s	26.0	1.73, s	26.0
13	6.55, dt (15.8, 1.5)	130.1	6.56, dt (15.8, 1.5)	130.0	6.56, dt (15.8, 1.5)	130.1
14	6.78, dt (15.8, 7.1)	138.5	6.79, dt (15.8, 7.1)	138.5	6.82, dt (15.8, 7.1)	139.0
15	2.27, m	36.0	2.27, m	36.0	2.27, m	36.0
16	1.55, m	23.2	1.56, m	23.2	1.55, m	23.2
17	0.98, t (7.4)	14.1	0.99, t (7.4)	14.1	0.98, t (7.4)	14.1
7‐OH[b]	–	–		–
specific rotation	${\left[\alpha \right]}_D^{24}$ = +160.0 (c 0.03; CHCl3)		${\left[\alpha \right]}_D^{24}$ = +159.3 (c 0.27; CHCl3)		${\left[\alpha \right]}_D^{22}$ = +179.3 (c 0.33; CHCl3)
specific rotation of ent‐series	–		${\left[\alpha \right]}_D^{25}$ =−206.0 (c 0.22; CHCl3)		${\left[\alpha \right]}_D^{21}$ =−160.3 (c 1.20; CHCl3)

[a] MeOD (δ in ppm, multiplicity, J in Hz). [b] OH group not detectible in MeOD.