Asymmetric synthesis of 2,4,5- substituted prolines through 1,3-dipolar addition reaction of N-arylidene menthyl esters of α-aminoacid with methyl acrylate

Proline and its derivatives constitute the important organic entities as organocatalyst, ACE inhibitors, bioactive molecules/intermediates to bioactive molecules as well as components of various natural products e.g. Kainic acid, (-)-domoic acid, etc. Due to its wide range of utility extensive studies have been made for the synthesis of 2, 3, 4 or 5 substituted prolines. One pot synthesis of 2,4,5-substituted prolines through 1,3-dipolar addition of various amino acids with homochiral acrylate has also been carried out successfully. Herein we wish to report the 1,3-dipolar addition of Schiff bases, where chiral auxiliary has been introduced in the Schiff bases and 1,3dipolar addition with methyl acrylate leading to the synthesis of 2(S),4(S),5(R)-substituted prolines has been achieved successfully

Asymmetric synthesis of 2,4,5- substituted prolines through 1,3-dipolar addition reaction of N-arylidene menthyl esters of α-aminoacid with methyl acrylate

1039-1042Proline and its derivatives constitute the important organic entities as organocatalyst, ACE inhibitors, bioactive molecules/intermediates to bioactive molecules as well as components of various natural products e.g. Kainic acid, (-)-domoic acid, etc. Due to its wide range of utility extensive studies have been made for the synthesis of 2, 3, 4 or 5 substituted prolines. One pot synthesis of 2,4,5-substituted prolines through 1,3-dipolar addition of various amino acids with homochiral acrylate has also been carried out successfully. Herein we wish to report the 1,3-dipolar addition of Schiff bases, where chiral auxiliary has been introduced in the Schiff bases and 1,3dipolar addition with methyl acrylate leading to the synthesis of 2(S),4(S),5(R)-substituted prolines has been achieved successfully

<span style="font-size:12.0pt;font-family: "Times New Roman";mso-fareast-font-family:"Times New Roman";mso-ansi-language: EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Acid catalyzed condensation of pyroglutamic acid with arylaldehydes: Synthesis of (3<i>R</i>, 7a<i>S</i>)-3-aryldihydropyrrolo[1, 2-<i>c</i>] oxazol-1, 5(3<i style="mso-bidi-font-style:normal">H</i>, 6<i style="mso-bidi-font-style:normal">H</i>) dione</span>

1781-1784A simple strategy for the synthesis of (3R, 7aS)-3-aryldihydro­pyrrolo [1, 2-c] oxazol-1, 5(3H, 6<i style="mso-bidi-font-style: normal">H)-diones as bicyclic hemi­aminals through acid catalyzed condensation of pyroglutamic acid with arylaldehydes has been described. This could be useful for the synthesis of complex natural products requiring α-substitution in proline or pyroglutamate skeleton

Synthesis of N-[3'-(acetylthio)alkanoyl] and N-[3'-mercaptoalkanoyl]-4-α (s)-(phenylmethyl) pyroglutamic acids and prolines as potent ACE inhibitors

Angiotensin converting enzyme (ACE) inhibitors have emerged as a revolution in antihypertensive therapy. Introduction of captopril, the first rationally designed ACE inhibitor, has encouraged researchers all over the world to design and synthesize target molecules controlling hypertension based on these lines. It has been observed that replacing proline part of captopril with 4-substituted prolines or 5-oxo-prolines led to significant enhancement in ACE inhibitory activity, and this observation prompted us to design and synthesize N-acyl 4-substituted pyroglutamates and prolinates with the objective of developing therapeutically better ACE inhibitors. Herein we describe an easy approach for N-acylation of 4-α (S)-(phenylmethyl) pyroglutamates with the aim of synthesizing N-[3'-(acetylthio)alkanoyl] and N-[3'-mercaptoalkanoyl]-4-α -(s)-(phenylmethyl) pyroglutamic acids and prolines as ACE inhibitors

An efficient and straight forward strategy for the synthesis of enantiomerically pure (S)-1-benzyl-5-(alkyl/aryl amino) methyl)-pyrrolidin-2-ones

936-939A simple, efficient and straightforward strategy for the synthesis of enantiomerically pure (S)-5-((alkyl/aryl amino) methyl)-pyrrolidin-2-ones from N-benzyl-5(S)-pyroglutaminol through Mitsunobu reaction has been described. These pyrrolidin-2-ones have great potential to act as asymmetric precursors for the synthesis of bioactive compounds/ natural products requiring suitably substituted aminomethyl group at C-5 of native pyrrolidin-2-ones