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Determination of the configuration at C-24 in stigmasterols by comparison of ¹³C NMR spectra

Example: 3-Hydroxystigmast-5-en-7-one (CDCl₃, 77.0 ppm)

Without substitution or oxygenation on D-ring and side chain, this rule is highly reliable. It should be noted that the C-24 epimers are identical in TLC behavior.