Abstract Deprotonation of the 3-trialkylsilyloxy-1, 4-diene 3a and subsequent electrophilic substitution of the non-isolated 3-trialkylsilyoxypentadienyllithium 4 gives the α-and γ- products 8 and/or 6 in good yields. Whereas alkylation of 4 proceeds with variable regioselectivity (Table 1) aldehydes and ketones attack preferentially the γ-position of 4 (Table 2). The desired γ-products 6 may be directly subjected to inter-and intramolecular [ ...
