A Versatile Synthesis of Four-, Five-, and Six-membered Cyclic Ketones Using Methyl Methylthiomethyl Sulfoxide

Article abstract of DOI:10.1246/bcsj.57.1637

Cyclization of 1,n-dihaloalkanes with methyl methylthiomethyl sulfoxide in the presence of a base (n-BuLi or KH) gave three-, four-, five-, and six-membered 1-methylsulfinyl-1-methylthiocycloalkanes.These cyclization products were easily converted to the corresponding ketones by acid hydrolysis except 1-methylsulfinyl-1-methylthiocyclopropane which afforded a complicated mixture.The combination of the cyclization with the acidhydrolysis thus provides a new method for synthesizing four-, five-, and six-membered cycloalkanones.Several representative preparations, such as those of substituted cyclobutanones, 3-cyclopentanone, and tetrahydro-4-pyrone are described.