Fig. 6.
Identification of 20,23-dihydroxyvitamin D3. (A) Expansion of proton–proton COSY correlations for 3-CH and 23-CH; (B) expansion of proton–proton TOCSY correlations for 3-CH and 23-CH; (C) expansion of proton–carbon HSQC showing groups having correlation to 3-CH and 23-CH (for details, see text).