91967-61-2Relevant academic research and scientific papers
ADDITION OF ORGANOMAGNESIUM REAGENTS TO RING EPOXY-KETONES V. 4,4-DIMETHYL-2,3-EPOXYCYCLOHEXANONE, AND 3,5,5-TRIMETHYL-2,3-EPOXYCYCLOHEXANONE
Sepulveda, Jose,Soriano, Concepcion,Roquet-Jalmar, Joaquin,Mestres, Ramon,Riego, Juan
, p. 189 - 192 (2007/10/02)
Stereoselectivities found for additions of ethynyl, vinyl, and ethylmagnesium bromides to 4,4-dimethylcyclohexanone oxide 4 are in agreement with a biassed 4a conformation of the substrate, and with a torsional strain effect by the oxirane C2-O bond.Thus, a 1:1 mixture is obtained for the small ethynyl group, whereas highly selective cis attack is found for the larger ethyl reagent.Additions to 3,5,5-trimethylepoxycyclohexanone are highly selective for any of the above organomagnesium reagents due to steric hindrance by the axial methyl group at C5, and trans adducts 14, 16 and 18 result, along with a small amount of the cis-ethynyl epoxycyclohexanol 15.Easy trans-hydroxy-epoxy interconversions have been observed for the trans-ethyl adducts 10 and 18, which are obtained along with their respective isomers 12 and 20.
