Stereochemistry of Dithianyllithium Addition to Cyclohexanone

Article abstract of DOI:10.1021/jo00199a033

The reaction of 2-phenyl-1,3-dithianyllithium (1-Li) with 4-tert-butylcyclohexanone in cyclohexane and tetrahydrofuran may proceed either with kinetic or thermodynamic control.In the latter case carbinol formation involves exclusively equatorial attack.In contrast, only kinetic control is seen in the reaction of the same ketone with 1,3-dithianyllithium (2-Li) or its mono-S-oxide (3-Li).No addition but only enolate formation occurs in solvent hexamethylphosphoric triamide; with 1-<2-phenyl-2-(1,3-dithianyl)>-4-tert-butylcyclohexanol reversal of the addition reaction is seen in this solvent.