Racemic beta- and gamma-hydroxy sulfides were resolved by Humicola lanuginosa lipase catalyzed transesterification using vinyl acetate both as acyl donor and solvent. The effect of substituents and spacer length on rate of reaction and enantioselectivity is observed.
Cyclization by Intramolecular Carbolithiation of Alkyl- and Vinyllithiums Prepared by the Action of Aromatic Radical Anions on Phenyl Thioethers. High Stereoselectivity in the Cyclization Accelerated by an Allylic Lithium Oxyanion<sup>1</sup>
The reductivelithiation of alkyl and vinyl phenyl thioethers by aromaticradicalanions is shown to be the most general method yet known for preparing organolithiums capable of intramolecular carbometalation of unactivated alkenes to produce five-membered rings and in one case a four-membered ring (in a far higher yield than known cases). The relative rates of cyclization for alkyllithiums are secondary