Approaches to the synthesis of cytochalasans. Part 10 . Cuprates as reagents for the formation of CC bonds

Based upon our novel concept for the total synthesis of cytochalasans, the model lactams 2–9 were treated with Bu 2 Cu(CN)Li 2 . The results of these conversions vary much from those obtained with Ph 2 Cu(CN)Li 2 , demonstrating the uncertainty of predictions in cuprate chemistry. The bicyclic compound 20 was prepared in good yield. However, all attempts to convert p ‐toluenesulfonate 20 into the Ph‐substituted derivative 21 , an intermediate for the synthesis of cyiochulusm B(1) , have failed so far.