A New Modulated Oxidative Ring Cleavage of α-Nitrocycloalkanones by Oxone®: Synthesis of α,ω-Dicarboxylic Acids and α,ω-Dicarboxylic Acid Monomethyl Esters
Michael Additions in Aqueous Media: “On-Water” and “In-Water” Processes from α-Nitro Ketones and Their Anions
作者:Giorgio Giorgi、Pilar López-Alvarado、Sonia Miranda、Jean Rodriguez、J. Carlos Menéndez
DOI:10.1002/ejoc.201201431
日期:2013.3
A variety of α,β-unsaturatedaldehydes and ketones gave very high-yielding Michael addition reactions with α-nitrocycloalkanones in water, at room temperature without added catalyst. These can be considered as one of the very few “on-water” Michael reactions known in the literature, because they took place in suspension or emulsion and at increased speed relative to the same transformations performed
Practical and User-Friendly Procedure for Michael Reactions of α-Nitroketones in Water
作者:J. Carlos Menéndez、Sonia Miranda、Pilar López-Alvarado、Giorgio Giorgi、Jean Rodriguez、Carmen Avendaño
DOI:10.1055/s-2003-42096
日期:——
A variety of α,β-unsaturated carbonyl derivatives gave selective Michael additions with several α-nitrocycloalkanones in water, at room temperature without any added catalyst, or in very dilute, aqueous solutions of potassium carbonate. Both preparative methods constitute new, environmentally benign and more efficient alternatives to previous procedures.
The reaction of α-nitro ketones to the corresponding α-hydroxy ketones under basic aqueous conditions, a novel transformation, was studied. The investigation revealed that the reaction is only possible with α-nitro ketones that are CH-acidic in the α′-position and readily deprotonated under the reaction conditions. The NO2/OH exchange was established to proceed with retention of configuration at the
Ring cleavage of 2-Nitrocycloalkanones with methanol/Amberlyst A 21 gave methyl Ï-nitroalkanoates, O2NCH2(CH2)nCO2Me where n = 3-6, 8-10, 13, in high yield. Subsequent Nef reaction gave the corresponding Ï-oxo compounds which were isolated, in the case of methyl 7-oxoheptanoate and methyl 8-oxooctanoate only, or reduced directly with sodium borohydride to give Ï-hydroxyalkanoates. A new formal synthesis of exaltolide (15-pentadecanolide) is also reported.
A General, Diastereoselective Synthesis of Highly Functionalized Bicyclo[n.3.1]alkane Systems Based on an Anionic Domino Reaction of α-Nitrocycloalkanones
作者:Giorgio Giorgi、Sonia Miranda、Miriam Ruiz、Jean Rodriguez、Pilar López-Alvarado、J. Carlos Menéndez
DOI:10.1002/ejoc.201001672
日期:2011.4
base-promoted Michael–aldol anionic domino reactions of cyclic α-nitro ketones and α,β-unsaturated aldehydes afforded bicyclo[n.3.1]alkanone systems of seven different ring sizes (n = 3–9), normally in excellent yields. This can be considered the first general method for the synthesis of this type of carbocycle. Furthermore, up to four stereocentres are generated, three of which are contiguous and include a functionalized