The isolation and identification of twelve new compounds formed on photolysis of ergosterol in ethanol are described. These include four C19 and C20 hydrocarbon photofragments derived by loss of ring A, two related vinyl ethers, and six toxisterols2. Three of the previously elusive toxisterols2 have a novel spiro-steroid structure isomeric with ergosterol. The other three are ethers containing the dihydrotachysterol chromophore. Photolysis of ...
