Amino Acids as Synthons for Heterocyclic Compounds**Dedicated to Professor Dr. Richard Neidlein on the occasion of his 65th birthday

A General Synthesis of Pyrroles and Fused Pyrrole Systems from Ketones and Amino Acids

“…Although conceptually related to the familiar Knorr pyrrole synthesis, in which α-oximino ketones are reduced to α-amino ketones and then reacted with β-diketones or β-keto esters to afford substituted pyrroles, the present method would offer the advantage of employment of BOC-α-amino aldehydes or ketones 1 that are readily available from a wide variety of amino acids. The advantageous application of amino acids as synthons for various heterocyclic systems, including pyrroles, has recently been summarized . In addition, the pyrrole synthesis outlined in Scheme utilizes simple ketones instead of the β-diketones or β-keto esters that are normally used in the Knorr synthesis, and it avoids the dicarbonyl intermediate 5 and subsequent alternative aldol reactions that lead to Fischer−Fink products 8 and 9 as well as the Knorr product 6 in the Knorr pyrrole synthesis (Scheme )…”

Alkyl 2-Substituted 3-(Dimethylamino)propenoates and Related Compounds - Versatile Reagents in Heterocyclic Chemistry

“…26,33,35,38,39,47 For compounds 2a, 4b, and 4i only single sets of signals were observed in both solvents. 35,47 For the compound 2l two sets of signals in the ratio 10:1 and 10:3, assigned to rotamers with respect to the partial double bond C1-C2, have been found in both, DMSO-d 6 and CDCl 3 . 47 Compound 2o exists as a single isomer in CDCl 3 solution, while in DMSO a mixture of two rotamers in a ratio 10:3 was observed (Scheme 7).…”

“…The orientation of groups around the double bond of the 3-(dimethylamino)propenoates 2a, 2l, 2o, 4b, 4e, 4g, 4i, 4l, and 4o-r has been studied by NMR using NOESY, ROESY, and HMBC techniques in DMSO-d 6 and CDCl 3 . 26,33,35,38,39,47 For compounds 2a, 4b, and 4i only single sets of signals were observed in both solvents.…”

Synthesis of heteroaryl substituted α‐amino acid derivatives, polyols, and related compounds

“…acids and sugars are excellent starting materials since they offer an easy access to suitable precursors of functionalized heterocyclic compounds [5][6][7][8].…”