60891-25-0Relevant academic research and scientific papers
Alkylation Reactions of 2-Methylpropyl 3-(2-Methylpropoxy)-5-oxocyclohex-3-ene-1-carboxylate
Mokbel, Luci,Savage, G. Paul,Simpson, Gregory W.
, p. 1727 - 1734 (2007/10/02)
The anion derived from 2-methylpropyl 3-(2-methylpropoxy)-5-oxocyclohex-3-ene-1-carboxylate was reacted with methyl iodide to give cis and trans isomers of 2-methylpropyl 6-methyl-3-(2-methylpropoxy)-5-oxocyclohex-3-ene-1-carboxylate.The reaction proceeded with high regioselectivity.A combination of n.m.r. experiments was used to determine that the major diastereomer was in a trans configuration.The dianion derived from 2-methylpropyl 3-(2-methylpropoxy)-5-oxocyclohex-3-ene-1-carboxylate methylated at C1 and C6 with a roughly equal proportion of cis and trans isomers.When treated with 1 equiv. of 1-bromo-3-chloropropane the same dianion alkylates at C1 to give 2-methylpropyl 1-(3-chloropropyl)-3-(2-methylpropoxy)-5-oxocyclohex-3-ene-1-carboxylate.
Reactions of Umpolung Reagents with Enol Ethers of β-Diketones: Sterically Induced Selectivity of the Dithiane Anion
Tobin, Paul S.,Basu, Swapan K.,Grosserode, Robert S.,Wheeler, Desmond M.S.
, p. 1250 - 1253 (2007/10/02)
In work on the synthesis of a tricyclic analogue of daunomycinone, the reactions of several umpolung equivalents of acetaldehyde with enol ether esters of 3,5-dioxocyclohexanecarboxylic acid have been examined.The dithiane reagent 1 and the sulfoxide 2 give 1,2 attack on the carbonyl group of the vinylogous ester system and also react at a similar rate with ester groups.The latter reaction can be retarded by using esters formed with isobutyl rather than methyl alcohol.In order to get selective attack on the carbonyl of the vinylogous esters in preference to thatof the ester, it is best to use reverse addition at low temperature.
