Stille/Diels−Alder Reaction Sequences: Diversity-Oriented Access to Novel Steroids

An efficient, diversity-oriented approach to novel steroid analogues possessing a C-5β configuration begins with the Stille cross-coupling of
enantiomerically pure cycloalkenylstannane trans-2 and enol triflate 3. The resulting diene trans-4 engages in Diels−Alder cycloaddition reactions
with a range of dienophiles to give, after removal of protecting groups, biologically interesting 6,7-disubstituted steroid analogues.