69849-23-6Relevant academic research and scientific papers
Trimethylsilylcyanid als Umpolungsreagens, VII. Nucleophile Acylierung von Carbonylverbindungen mit α,β-ungesaettigten Aldehyden
Huenig, Siegfried,Oeller, Manfred
, p. 959 - 967 (2007/10/02)
The addition products 9 - 12 of trialkylsilyl cyanide with conjugated aldehydes react as their anions 9A - 12A exclusively in the α-position with ketones and aldehydes, accompanied by a 1,4-O,O-silyl rearrangement (13, 15, 18, 19).The formation of 2:1 add
Three-Carbon Annelations. Regiocontrolled Reactivity of Trimethylsilyl- and Ethoxyethyl-Protected Cyanohydrins. Versatile Homoenolate and Acyl Anion Equivalents
Jacobson, Richard M.,Lahm, George P.,Clader, John W.
, p. 395 - 405 (2007/10/02)
The trimethylsilyl- (2) and ethoxyethyl- (4) protected cyanohydrins of α,β-unsaturated aldehydes are utilized as three-carbon annelation reagents.Metalated reagent 2 displays exclusive α reactivity with aldehydes and ketones at -78 deg C.Metalated reagent 4 displays exclusive α reactivity at -78 deg C and exclusive γ reactivity at 0 deg C.Reagent 4 thus allows for complete regiocontrol in its addition to aldehydes and ketones which permits selective addition of either a homoenolate or an acyl anion equivalent.Metalation of the α product 11 at -78 deg C with subsequent warming to 0 deg C produces exclusively the γ product, confirming the reversible nature of the addition to the carbonyl.The derived α '-trimethylsiloxy enones 17 (R3=Me3Si), α '-hydroxy enones 17 (R3=H), α '-acetoxyenones 17 (R3=Ac), and γ-lactones 10 are useful cyclopentenone precursors.Treatment of 17 with p-TsOH in toluene at reflux produces cyclopentenones.The reaction proceeds via the postulated intermediacy of a pentadienyl cation 15 which undergoes in situ electrocyclic ring closure.
