1: lithium diisopropylamide, hexamethylphosphoric triamide, 4,4-pentamethylene-1,2-dithiolane / tetrahydrofuran / 4 h / Ambient temperature 2: 1.) diisopropylamine, butyllithium, 2.) hexamethylphosphoric triamide / 1.) THF, hexane, room temperature, 2.) THF, room temperature, 4 h View Scheme

4,4-pentamethylene-1,2-dithiolane; N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide in tetrahydrofuran 4 h; Ambient temperature; Yield given. Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;

4,4-pentamethylene-1,2-dithiolane; N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide in tetrahydrofuran 4 h; Ambient temperature; Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;

N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide in tetrahydrofuran 4 h; Ambient temperature; Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;

4,4-pentamethylene-1,2-dithiolane; N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide in tetrahydrofuran 4 h; Ambient temperature; Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;

N,N,N',N',N'',N''-hexamethylphosphoric triamide; lithium diisopropyl amide in tetrahydrofuran 4 h; Ambient temperature; Further byproducts given. Yields of byproduct given. Title compound not separated from byproducts;