(1S,3R,6R)-bis(tert-butyldimethylsilyloxy)-9,10-seco-ergosta-5,7(E),10(19),22(E)-tetraene SO2 adduct

(1S,3R,6S)-bis(tert-butyldimethylsilyloxy)-9,10-seco-ergosta-5,7(E),10(19),22(E)-tetraene SO2 adduct

1(S),3(R)-bis[(tert-butyldimethylsilyl)oxy]-20(R)-formyl-9,10-secopregna-5(E),7(E),10(19)-triene