Within a program designed for the study of partial-synthetic approaches to certain natural products, it became desirable to prepare a variety of steroidal compounds containing an aromatic B-ring. Of representatives of this type, the literature3 describes particularly those corresponding to ergosterol (2), 22-dihydroergosterol (3), their epimers (4), and cholesterol (5).I n our preparative work we used, with some modifications, the procedure introduced by Windaus and Borgeaud (2), namely the photooxidation of the appropriate A5y 7-steroid and subsequent decomposition of the bis-A6, 8(9)-diene (6). I n the first reaction, the important factor, in regard to yield, was the selection of the proper solvent mixture. Thus, in the preparation of bisergostatrienol (111) from ergosterol (I), by using tetrahydrofuran instead of benzene as the second solvent, we could increase the yield by 15 to 20%. We found that the use of any one particular fluorescein sensitizer, or the use of a mixture of these sensitizers (7), had no effect on the final yield. By employing as the light source an arrangement of fluorescent lamps, we have devised a simple and convenient procedure for the photooxidation. I n this manner we prepared: bisergostatrienol (111) from ergosterol (I), bis(methyl-3~-acetoxybisnorcholadienate) (IV) from methyl -3p -acetoxy-A5* -bisnorcholadienate (11), bis(3p -acetoxy -22 -iso~pirostadiene)~ (X) from 3/3-a~etoxy-A~~~-22-isospirostadiene~ (IX). Boiling, under reflux, the solutions of the bis-compounds in diethylene glycol monoethyl ether, readily produced the respective derivatives containing an aromatic B-ring: neoergosterol (V), methyl EY -(36 -acetoxy -5 , 7 , 9 -estratriene -17 -yl) -propionate (VIIId), previously obtained by Jacobsen (9) by degradation of neoergosterol, and 3j3-acetoxy-Ar"s 7 , 9(10)-22-iso-19-norspirostatriene (XIb). The yields obtained varied from 75-95% of the t h e~r y .~The ultraviolet spectra of V, VIII, and XI showed maxima a t 269-270 mp, characteristic of the aromatic B-riiig (10). The infrared spectra showed identical bands in the region of 810 cm-l, which we found characteristic of the aromatic ring in these compounds.6