Selective lithiation of 1-chloro-n-phenylsulfanylalkanes

Abstract

This paper is dedicated to Professor Lutz F. Tietze on occasion of his 65th anniversary The reaction of different 1-chloro-n-phenylsulfanylalkanes 5 with 2 equivalents of lithium naphthalene at -78°C followed by addition of a carbonyl compound [ButCHO, Et2CO, (CH2) 5CO] leads, after hydrolysis with water, to the expected sulfanyl alcohols 8 through a selective lithiation of the carbon-chlorine bond. When an excess of lithium (1:4 molar ratio) is added to the reaction mixture before the hydrolysis and the system is allowed to reach -50°C during 1.5 h, lithiation of the remaining carbon-sulfur bond takes place. The addition of a second carbonyl compound (ButCHO, PhCHO), followed by hydrolysis, gives differently substituted diols 3. ©ARKAT USA, Inc.