4- Nitro-Estrone

Similarly the method devised for the determination of estrone gave the 4-nitro-estrone derivative.The procedure is ... 

Thus, the rutro group at the illylic posmou is replaced by aucleophiles in the following three ways (1) assistance by transmon met il, f2 assistance by Lewis acids, and Ci) assistance by proton Zard and coworkers have reported a short total synthesis of estrone derivanves, where acid catalyzed dlylic 1,3-shift of nitro group Is used as a key step as shown in Scheme 7 4 ... 

Samajdar et al. (2000) performed nitration of aromatic compounds by bismnth nitrate on catalysis with montmorillonite KSF. The reaction develops in THF suspension on steering dnring 10 min. Nitration of anisole proceeds strictly in the para position (91% yield after 10 min), bnt in case of phenol, the reaction occnrs to be nonregioselective and 3 1 mixture of para and ortho nitro prod-nets is formed with a common yield of 89%. Nitration of estrone (the steroid phenol) also leads to 1 1 mixtnre of para and ortho nitrophenolic steroids in 94% yield. 

Fig. 9 Enzymatic mechanism involved in the formation of estrogens. A The sulfatase pathway. B,C Structure of the potent STS inhibitors EMATE and COUMATE. D New pharmacophore for the inhibition of estrone sulfatase R general carbon backbone (aromatic or aliphatic), X electron withdrawing groups (e.g. nitro), Y additional functionality including fused or adjacent/remote ring structures so as to meet the log requirement...

Cyclopropartation. Chemists at Schering AG (Berlin) discovered a novel cydopropanation in the reaction of the derivative (1) of estrone with nitromethane and sodium methoxide in methanol. The product is 2, evidently formed by Michael addition of CH2NO2 and ring closure with elimination of the nitro group. This... 

Nitro stron (2)/ Claylen was prepared from a mixture of FefNOsJa HjO (45 g Oil mol), K 10 bentonite clay and MeaCO (750 mL) Freshly prepared Clayfen (2 0 g) was added to estrone 1 (0 54 g 2 mmol) and PhMe (150 mL) The suspension was stirred overnight at 20° and filtered under vacuum The yellow filtrate was purified by column chromatography on sdica gel (n-hexane ElOAc 8 2) Evaporation ol the corresponding fraction afforded 0 347 g of 2 (55%) mp 178 180 C... 

---