Scheme 24.
Alternative synthetic routes to 57 are depicted, respectively, in red and in blue. Common steps are depicted in black (TMEDA=N,N,N′,N′‐Tetramethylethylenediamine).
Alternative synthetic routes to 57 are depicted, respectively, in red and in blue. Common steps are depicted in black (TMEDA=N,N,N′,N′‐Tetramethylethylenediamine).