Regioselective synthesis of 5-alkylidene and 5-(iodoalkylidene)-pyrrol-2(5H)-ones by halolactamisation of (2Z,4E)-dienamides and (Z)-alk-2-en-4-ynamides
Stereo- and regioselective synthesis of 5-alkylidene (arylidene) and 5-(iodoalkylidene)-pyrrol-2(5H)-ones was achieved from (2Z,4E)-dienamides and (Z)-alk-2-en-4-ynamides by halocyclisation reaction. Selectivity was found to be highly dependent on the nature of the substituents and on the tempetature. (C) 2001 Elsevier Ltd. All rights reserved.
Efficient Regio- and Stereoselective Synthesis of 5-Alkyl(aryl)idene- and 5-[Iodoalkyl(aryl)idene]-1H-pyrrol-2(5H)-ones via Electrophilic Cyclization
A variety of substituted 5-alkyl(aryl)idene- and 5-[iodoalkyl(aryl)idene]-1H-pyrrol-2(5H)-ones were readily prepared with good yields under very mild reaction conditions by the iodocyclization of (2Z,4E)-dienamides and (Z)-alk-2-en-4-ynamides with iodine monochloride. 3-Ylidene-isoindolin-1-ones were also synthesized in moderate to good yields under the same conditions. The methodology proceeded with total regioselectivity in all cases and was applied to the synthesis of new unsaturated lactam compounds.