Diastereoselective Formation of Dithioacetal Oxides from Aliphatic Sulfines under Thermodynamic Control

✍ Scribed by Florence Corbin; Carole Alayrac; Patrick Metzner

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 357 KB
• Volume: 1999
• Category: Article
• ISSN: 1434-193X
• DOI: 10.1002/(sici)1099-0690(199911)1999:11<2859::aid-ejoc2859>3.0.co;2-1

✦ Synopsis

Protonation of α-sulfinyl carbanions 3, resulting from the carbanions 3, at which protonation occurs under kinetic control and with retention of configuration with the selective thiophilic addition of organolithium compounds to aliphatic sulfines 2, provided dithioacetal oxides 4 (63-94% assistance of the lithium cation. Moreover, the stereochemistry could be totally reversed by converting the yield). The diastereomeric ratio ranged from 52:48 up to 100:0 with sterically hindered substituents. Thus, (1S*,SS*)-lithiated anion intermediate into an aluminium "ate" complex. Thus, (1R*,SS*)-2,2-dimethyl-1-methylsulfanyl-1-2,2-dimethyl-1-methylsulfanyl-1-methylsulfinylpropane (4ca) was obtained as a single isomer. The origin of the methylsulfinylpropane (4ca) was selectively obtained by this method (dr = 0:100). stereoselectivity is rationalized in terms of a thermodynamic equilibrium between the two diastereomers of α-sulfinyl