Base-Controlled Selective Conversion of Michael Adducts of Malonates with Enones in the Presence of Iodine

Abstract

An efficient base-controlled selective conversion of the Michael adducts of malonates with enones in the presence of iodine is reported. Highly functionalized cyclopropane, oxetane, and α-hydroxylmalonate derivatives are obtained selectively using DBU, Na(2)CO(3), and NaOAc as the base, respectively. O(2) was identified to be crucial to the formation of oxetane and α-hydroxylmalonate derivatives.

Unexpected Iodine-Promoted Aerobic Oxidation of α-Cyano-δ-keto Esters: A Facile Synthesis of α,δ-Dicarbonyl Esters

“…Based on the above experimental results and on the previous reports, 17,10 a plausible reaction mechanism is proposed in Scheme 2. The reaction begins with iodination of 1a to give iodide A. Homolytic cleavage of the C-I bond of A then gives carbon radical B, which reacts with oxygen from air to generate peroxyl radical C. 17…”

Synthetic Applications of Aroyl‐ and Nitro‐substituted 2‐Aryl‐Cyclopropane‐1,1‐Dicarboxylates

“…in toluene or DCM at room temperature, the cyclopropanes 1 and 2 were produced in excellent yields. The iodine‐incorporated Michael adducts A were produced as intermediates in the reactions and the adducts then underwent DBU‐promoted S N 2 ring closure to give the products. The main advantage of our procedure over other methods is the exclusive formation of the trans ‐cyclopropanes with no sign of cis ‐cyclopropanes.…”

A One Pot Synthesis of Dehydrohedione (DHH) from a Hedione® Precursor

“…A soln. of methyl (2,4-dichloro-3-oxo-2-pentylcyclopentyl)acetate (see 6f, 0.5 g, 1.0 mmol) 31 Oxidation of 2a (I 2 , AcONa, THF, 35°C, air, 78% yield, in analogy to [131] [132] ), afforded 3c, besides a diol as minor side product (see Experimental Section). The corresponding iodide could not be isolated when the reaction was performed under Ar.…”