66228-07-7Relevant academic research and scientific papers
[1,2]-Wittig rearrangement of a lithioalkyl benzyl ether with inversion of configuration at the carbanion C atom. Diastereoselective reductions of cyclohexyl radicals with LI+ arene-
Hoffmann, Rolf,Rueckert, Tanja,Brueckner, Reinhard
, p. 297 - 300 (2007/10/02)
Treatment of the diastereomeric O, Se-ketals cis- or trans-4 with lithium naphthalenide provided, through stereoselective reduction of the radical intermediate 5, the axially lithiated cyclohexyl ether trans-6. trans-6 gave the equatorially benzylated cyc
Synthetic utility and mechanistic studies of the aliphatic reverse brook rearrangement
Linderman, Russell J.,Ghannam, Ameen
, p. 2392 - 2398 (2007/10/02)
The aliphatic reverse Brook rearrangement has been examined in detail. Transmetalation of [α-[(trialkylsilyl)-oxy]alkyl]trialkylstannanes occurs via a complex equilibrium favoring the most stable carbanion. The aliphatic reverse Brook rearrangement is driven forward by the rapid migration of silicon from O to C in a transient α-silyloxy carbanion due to the formation of the more stable lithium alkoxide. Cross-over experiments have shown that the rearrangement is an intramolecular process while incorporation of a radical trap revealed that the rearrangement does not involve radical intermediates. Studies of configurationally fixed stannanes derived from 4-tert-butylcyclohexanone concluded that the rearrangement occurs with retention of configuration. Preparation and reverse Brook rearrangement of optically active (S)-[α-[(trimethylsilyl)oxy]-hexyl]tributylstannane (98% ee) provided 1-(trimethylsilyl)hexanol in 97% ee. The synthetic utility of this method for the preparation of a variety of (α-hydroxyalkyl)trialkylsilanes from aldehydes has also been demonstrated.
Silanes in Organic Synthesis. 9. Enesilylation as a Method for 1,2-Carbonyl Migration within Ketones and for Conversion to 1,2-Transposed Allylic Alcohols
Fristad, William E.,Bailey, Thomas R.,Paquette, Leo A.
, p. 3028 - 3037 (2007/10/02)
Vinylsilanes are shown to be valuable synthetic intermediates in useful transformations of ketones.The epoxidation of vinylsilanes followed by lithium aluminium hydride reduction and oxidation with chromic acid and sulfuric acid in a two-phase (ether/water) system often gives high yields of 1,2-transposed ketones.With singlet oxygen and sequential sodium borohydride reduction, 2-trimethylsilyl alcohols are produced in which the α position of the parent ketone has been regiospecifically oxygenated.Fluoride ion promoted desilylation completes the conversion to the migrated allylic alcohol.
