Synthesis Total synthesis The synthesis developed by the Bachmann group started from Butenand's ketone – the 7-methoxy structural analog of 1,2,3,4-tetrahydrophenanthren-1-one – and which can be readily prepared from 1,6-Cleve's acid. The approach was based on well-established transformations like the Claisen condensation, the Reformatsky reaction, the Arndt–Eistert reaction, and the Dieckmann condensation. Nicolaou described this preparation as ending the era preceding the post-World War II work of Robert Burns Woodward that introduced enantioselective synthesis; in this synthesis, a mixture of stereoisomers were prepared and then resolved, and the choice of target was partly because of the existence of only two chiral carbons and hence only four stereoisomers. 700px The overall yield of the synthesis was 2.7% based on a twenty-step process starting from Cleve's acid.
Equilenin
Transfluthrin
Birtoxin
Urofollitropin
Equine estrogen
Mucrocetin
Otenaproxesul
Chlormerodrin