名称:
A Rapid Access to Both Enantiomers of 1,2,3,4-Tetranor B-Trienic 18,18,18-Trifluorosteroids. The First Enantiocontrolled Total Synthesis of 18,18,18-Trifluorosteroids
摘要:
Chiral A-tetranor B-trienic 18,18,18-trifluorosteroid 2a and its enantiomer 1a were synthesised by the thermolysis of chiral olefinic benzocyclobutenes 7b and 7a which were in turn prepared by the aldol reaction of chiral oxazolidinone 5 and 11 with 2-(4-methoxybenzocyclobutenyl-1)-acetaldehyde as a key step. The compound 1a was then transformed into 18,18,18-trifluorosteroid 9 via the ketone 13 and the diketone 14.