A FACILE ROUTE TO α-IMINO ACETALS AND THE CORRESPONDING MONOACETAL DERIVATIVES OF α-DIKETONES WITH COMPLETE REGIOCHEMICAL CONTROL
Treatment of representative orthoesters (2) with pyruvonitrile (3) afforded the corresponding α,α-diethoxynitriles (4) in 65-80percent yields.Depending upon the conditions used to protonate the initial adduct, subsequent addition of an organolithium (5) or Grignard reagent to the latter (4) led to the obtention of either α-imino acetals (6) or the corresponding monoprotected α-diketones (7) in >90percent yield.
A Sterically Congested α-Cyanoamine as a Cyanating Reagent: Cyanation of Acetals and Orthoesters
The cyanation of acetals and orthoesters by using a sterically congested α-cyanoamine as a cyanating reagent was investigated. The α-cyanoamine effectively facilitated cyanation in the presence of trichlorosilyl triflate to produce a variety of cyanated adducts in excellent yields. Analysis of the reaction mixture by 1H NMR spectroscopy revealed that trichlorosilyl triflate produced an oxocarbenium cation species as an intermediate.
AN EXPEDITIOUS ROUTE TO MONOPROTECTED α-KETO ALDEHYDES WITH CONTROL OF REGICHEMISTRY
Treatment of representative orthoesters (2) with pyruvonitrile (3) afforded the corresponding α,α-diethoxynitriles (4) in 65-85percent yields.Subsequent reduction of the latter using lithium aluminium hydride, followed by careful hydrolysis of the aldimine intermediates, led to the procurement of α,α-doalkoxy aldehydes (5) in 80-90percent yield.
Babler, James H.
p. 355 - 358
(2007/10/02)
More Articles about upstream products of 77426-90-5