Alkyl derivatives homocoupling reactions

Combination of the reagents TiCU, BuaN, and TMSOTf, was reported to be effective for Claisen condensation, as exemplified in Eqs (42) and (43) [129]. When acyl-oxazolidinones were subjected to reaction with TiCU and a tertiary amine, homocoupling reaction at the a-position of the acyl group took place to give succinic acid derivatives [146], The lithium enolate of an ester or amide has been alkylated with an (N,C>)-acetal in the presence of Ti(0-/-Pr)4 (Eq. 44) [147,148]. 

J.W. Morzycki and co-workers described the synthesis of dimeric steroids to be used as components of artificial lipid bilayer membranes. The key coupling of two steroid derivatives was achieved by the Wurtz reaction. The steroid primary alkyl iodide was dissolved in anhydrous toluene and treated with an excess of sodium metal. After 20h of reflux, the desired homocoupled product was obtained in moderate yield along with a considerable amount (36%) of the reduced compound. 

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