Thiophilic Addition of Organolithiums to Aliphatic Sulfines Spontaneous Conversion of Dithioacetal Oxides into Ketones

Abstract

Since the first evidence¹ of a thiophilic addition of organolithiums to sulfines by Schultz and Schlessinger this attractive reaction has received some applications,^2-4 mostly due to the group of Zwanenburg,^2,4 but these are limited to aromatic and non enethiolizable sulfines. Our recent synthesis of aliphatic sulfines^5-7 opened the way to the extension of this reaction. However there was a major concern: competition between addition and deprotonation, as organolithiums are highly basic and the α protons of sulfines have been assumed⁸ to be rather acidic.