. Author manuscript; available in PMC: 2006 Jul 4.

Published in final edited form as: J Org Chem. 2003 Oct 3;68(20):7841–7844. doi: 10.1021/jo034738l

TABLE 1.

Comparison of the ¹H NMR Chemical Shifts^a (δ) of Synthetic 3-Hydroxy-(2,4,6)-trimethylheptanoic Acid Diastereomers with the Natural Fragment

natural fragment^b δ, multiplicity (J), H	(R,R,R)-3 δ, multiplicity (J), H	(S,R,R)-3 δ, multiplicity (J), H	(S,R,S)-3 δ, multiplicity (J), H	(R,R,S)-3 δ, multiplicity (J), H
0.84, d (6.8), 3H	0.84, d (6.5), 3H	0.85, d (6.4), 3H	0.84, d (6.5), 3H	0.85, d (6.6), 3H
0.92, d (6.8), 3H	0.92, d (6.6), 3H	0.90, d (6.5), 6H	0.89, d (6.5), 3H	0.86, d (6.5), 3H
0.96, d (5.8), 3H	0.95, d (6.8), 3H		0.95, d (6.5), 3H	0.89, d (6.6), 3H
1.12–1.18, m, 2H	1.12–1.18, m, 2H	1.04, m, 1H	1.07, m, 2H	1.16, m, 1H
1.26, d (7.7), 3H	1.23, d (7.2), 3H	1.22, d (7.1), 3H	1.22, d (7.0), 3H	1.18, d (6.7), 3H
		1.49, m, 1H		1.24, m, 1H
1.64, m, 1H	1.64, m, 1H	1.62, m, 1H	1.66, m, 2H	1.66, m, 1H
1.70, m, 1H	1.69, m, 1H	1.66, m, 1H		1.70, m, 1H
2.73, quintet (7.7), 1H	2.74, dq (7.1,7.1), 1H	2.74, dq (3.5,3.5), 1H	2.72, dq (6.0,6.0), 1H	2.66, dq (7.5,7.5), 1H
3.48, dd (4.1, 7.7), 1H	3.48, dd (6.4, 6.4), 1H	3.67, dd (3.4, 7.7), 1H	3.68, dd (5.5, 5.5), 1H	3.61, dd (3.3, 8.3), 1H

All chemical shifts are reported in ppm and were measured in CDCl₃. Coupling constants (J) are expressed in Hz.

Spectral data for natural fragment are reproduced from ref 1.