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Synthesis of spirolactones by 1,3-dipolar cycloadditions to methyl (S)-3-[(E)-cyanomethylidene]-2-oxotetrahydrofuran-5-carboxylate

✍ Scribed by Samo Pirc; Simon Rečnik; Marko Škof; Jurij Svete; Ljubo Golič; Anton Meden; Branko Stanovnik

Book ID
102338921
Publisher
Journal of Heterocyclic Chemistry
Year
2002
Tongue
English
Weight
96 KB
Volume
39
Category
Article
ISSN
0022-152X

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✦ Synopsis

Abstract

Dedicated to Professor Emeritus Miha Tišler on the occasion of his 75th birthday

Treatment of methyl (S)‐5‐[(E)‐(dimethylamino)methylidene]‐2‐oxotetrahydrofuran‐5‐carboxylate (2) with potassium cyanide in acetic acid gave (S)‐5‐[(E)‐cyanomethylidene]‐2‐oxotetrahydrofuran‐5‐car‐boxylate (3), which was used as chiral dipolarophile in 1,3‐dipolar cycloadditions. Reactions of 3 with diazomethane (4) and nitrile oxides 5a‐c afforded spirolactones 6–8 in 24‐34% diastereomeric excess, while with diazomethane (4) in the presence of triethylamine, methyl 3‐cyanomethyl‐2‐methoxyfuran‐5‐carboxylate (12) was obtained.

📜 SIMILAR VOLUMES

Stereoselective 1,3-Dipolar Cycloadditio
Stereoselective 1,3-Dipolar Cycloadditions to (S)-1-Benzoyl-3-(cyanomethylidene)-5-(methoxycarbonyl)pyrrolidin-2-one
✍ Marko Škof; Jurij Svete; Branko Stanovnik; Ljubo Golič; Simona Golič-Grdadolnik; 📂 Article 📅 1998 🏛 John Wiley and Sons 🌐 German ⚖ 178 KB 👁 1 views

Benzoyl-3-[(E)-cyanomethylidene]-5-(methoxycarbonyl)pyrrolidin-2-one (5) was prepared in four steps from l-pyroglutamic acid (1). 1,3-Dipolar cycloadditions of diazomethane ( 6) and 2,4,6-trimethoxybenzonitrile oxide (7) gave substituted 1,2,7-triazaspiro[4.4]non-1-en-6-one 12 and 1-oxa-2,7-diazaspi

Isolation of Methyl (RS)-1-tert-Butoxyca
Isolation of Methyl (RS)-1-tert-Butoxycarbonyl-3-cyanomethyl-1,2-dihydro-2-oxo-5H-pyrrole-5- carboxylate, the Key-Intermediate in Base-Catalyzed Formation of Racemic Products by 1,3-Dipolar Cycloadditions to Methyl (S)-1-tert-Butoxycarbonyl-3- [(E)-cyanomethylidene]-2-pyrrolidinone-5-carboxylate.
✍ Marko Skof; Samo Pirc; Simon Recnik; Jurij Svete; Branko Stanovnik; Ljubo Golic; 📂 Article 📅 2003 🏛 John Wiley and Sons ⚖ 185 KB 👁 2 views

## Abstract For Abstract see ChemInform Abstract in Full Text.

Isolation of methyl (RS)-1-tert-butoxyca
Isolation of methyl (RS)-1-tert-butoxycarbonyl-3-cyanomethyl-1,2-dihydro-2-oxo-5H-pyrrole-5-carboxylate, the key-intermediate in base-catalyzed formation of racemic products by 1,3-dipolar cycloadditions to methyl (S)-1-tert-butoxycarbonyl-3-[(E)-cyanomethylidene]-2-pyrrolidinone-5-carboxylate
✍ Marko Škof; Samo Pirc; Simon Rečnik; Jurij Svete; Branko Stanovnik; Ljubo Golič; 📂 Article 📅 2002 🏛 Journal of Heterocyclic Chemistry 🌐 English ⚖ 81 KB

## Abstract Cycloadditions of various 1,3‐dipoles to methyl (__S__)‐1‐__tert__‐butoxycarbonyl‐3‐[(__E__)‐cyanomethylidene]‐2‐pyrrolidinone‐5‐carboxylate (**9**) were studied. Reactions of **9** with diazomethane (**10**) and 2,4,6‐trimethoxy‐benzonitrile oxide (**11**), carried out under neutral co