Pregn-4-en-3,20-dione

In 1973 D-homo corticosteroids (109—112), eg, D-homo-9a-fluoroprednisolone acetate (111) were reported to have antiinflammatory activity (107). Compounds such as 21-acetoxy-llp-fluoro-9a-chloro-17aa-hydroxy-D-homo-pregn-4-en-3,20-dione (110) had especially strong topical activity with weak systemic activity (108). Other preparations of D-homocorticoids included... 

In contrast to this, hydrolysis of 17a,20 20,21-bismethylenedioxy-19-nor-9y ,10a-pregn-4-en-3-one using aqueous 90% formic acid at reflux temperature for 3 min gives an overall yield of 17a,21-dihydroxy-19-nor-9, 10a-pregn-4-ene-3,20-dione 21-formate of 12%. 

Pregn-4-ene-3,20-dione) (17P-Hydroxy-19-norandrost-4-en-3-one) Figure 53-12 Structural formulas of progesterone and 19-nortestosterone. 

Fig. 13.3. Illustration of nomenclature rules (I) 5a-androstan-3a-ol, (II) 5a-androstan-3 -ol, (III) androst-5-ene, (IV) androst-5-ene-3, l 7 -diol, (V) 3 -hydroxyandrost-5-en-l 7-one (dehydroepian-drosterone), (VI) 11 -21-dihydroxypregn-4-ene-3,20-dione (corticosterone), and (VII) 21-hydroxy-pregn-4-ene-3,l 1,20-trione (11-dehydrocortico-sterone). (Dorfman and Ungar, 1965.)...

Nor-17a-pregn-4-en-20-yn-17 -ol, 42B, 397 19-Norpregn-4-ene-3,20-dione, 45B, 559 3-Methoxy-1 7/3-hydroxymethyl-estra-1,3,5(10)-triene, 46B,... 

Periodic Acid Degradation 17a,20 -Dihydroxy-4,4,6,16a-tetramethyl-pregn-5-en-3-one (0.3 g) is dissolved in 30 ml of methanol and treated with an aqueous solution of 0.25 g of periodic acid in 5 ml of water at room temperature for 17 hr. On dilution with water, the resultant crystals are collected by filtration, washed well with water, and dried to give 0.26 g mp 158-160°. Recrystallization from hexane-acetone gives 0.24 g (90%) of 4,4,6,16a-tetramethylandrost-5-ene-3,17-dione mp 160-161° [aj —6° (CHCI3). 

Cyano-17-hydroxyandrost-4-en-3-one, 135 20-Cy ano-21 -hydroxy-5/3-pregn-17(20) -ene-3,11-dione 21-raethyl ether, 224 10 -Cyano-19-norandrost-5-ene-3,17-dione bis-ethylene ketal, 278 10 -Cyano-19-norpregn-5-ene- 3/3,20/3-diol diacetate, 270... 

Diazocyclopropane adds to a pregn-16-en-20-one to give a pyrazole derivative, while a 4-en-3-one undergoes ring expansion to form A-homo-products. The formation of compounds (95) and (96) from pregna-4,16-diene-3,20-dione (94)... 

The synthesis of 6a-methyldigitoxigenin acetate (394) has been reported according to Scheme 19.198 Pregn-4-en-21-ol-3,20-dione was converted into its 6a-methyl derivative (387) using a previously described five-step reaction sequence biological hydroxylation furnished the 14a,12-diol (388) and reduction of the derived 21-acetate gave the 5/3-dihydro-steroid (389). Dehydration furnished the A14-olefin (390) which was converted into the 21-mesylate and thence into the lactone (391) by reaction with the monoethyl ester of malonic acid. The crude lactone was decarbox-ylated, reduced to the 3/3-alcohol (392), and converted into the bromohydrin (393) via its 3/3-acetate and thence by debromination into 6a-methyldigitoxigen 3-acetate... 

Fig. 125. Lengths of run of sterols and steroids of various polarities in 6 solvent systems of different eluotropic properties (Nos. 1—6 below). Substances 1 tetra-hydrocortisol 2 cortisol 3 cortisone 4 corticosterone 5 oestradioI-17/ 6 5/5-pregnane-3a,20a-diol 7 oestrone 8 testosterone 9 pregn-5-en-3j5-ol-20-one 10 androst-4"ene-3,17-dione ii deoxycorticosterone 12 progesterone 73 cholesterol 14 cholesteryl acetate 15 cholestane...

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