Figure 3 | Scientific Reports

Figure 3

From: Investigation of 20S-hydroxyvitamin D3 analogs and their 1α-OH derivatives as potent vitamin D receptor agonists with anti-inflammatory activities

Figure 3

Synthesis of 20S(OH)D3 analog 13 and its 1α-OH derivative 14. Reagents and conditions: (a) isopropyl bromine, NaH, THF, r.t., overnight. (b) TBAF, THF, r.t., 12 h. (c) Ac2O, pyridine, DMAP, 6 h. (d) dibromantin, AIBN, benzene: hexane (1:1), reflux 20 min; TBAB, THF, r.t., 75 min, then TBAF, r.t., 50 min. (e) CSA, MeOH:DCM (1:1), 0 °C - r.t., 12 h. (f) aq. KOH, MeOH, 2 h. (g) UVB, Et2O, 15 min. (h) EtOH, reflux, 3 h. (i) HPLC, MeCN:H2O. (j) CYP27B1.

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