A simple and stereoselective synthesis of 7‐azabicyclo[2.2.1]‐heptane‐1,2,3,4‐tetracarboxylates

Abstract

The photoinitiated reaction of 1,1′‐bis(methoxycarbonyl)divinylamine with various maleates and fumarates afforded novel 7‐azabicyclo[2.2.1]heptane‐1,2,3,4‐tetracarboxylates. The spectral investigation of the products showed that the reaction proceeded stereoselectively, retaining the original configuration of the reagents.

Chemistry of 7-Azabicyclo[2.2.1]hepta-2,5-dienes, 7-Azabicyclo[2.2.1]hept-2-enes, and 7-Azabicyclo[2.2.1]heptanes

“…128 The photoinitiated reaction of 1,1′-bis(methoxycarbonyl)-divinylamine (133) with dimethyl maleate and dimethyl fumarate was also reported to afford 7-azabicyclo[2.2.1]heptane-1,2,3,4-tetracarboxylates 134 and 135, respectively (Scheme 33). 129 This reaction was found to proceed stereoselectively, retaining the original configuration of the dipolarophiles. Compound 133 was also found to react with dialkyl acetylenedicarboxylates to give tetraalkyl 7-azabicyclo[2.2.1]hept-2-ene-1,2,3,4-carboxylates.…”

“…Mariano et al have described photocyclization reactions of 5-vinyl-1-pyrrolinium perchlorates 130 upon irradiation in methanol to furnish the intramolecular cycloaddition adduct 131 with a trace amount of the endo -methoxy isomer 132 (Scheme ) . The photoinitiated reaction of 1,1‘-bis(methoxycarbonyl)divinylamine ( 133 ) with dimethyl maleate and dimethyl fumarate was also reported to afford 7-azabicyclo[2.2.1]heptane-1,2,3,4-tetracarboxylates 134 and 135 , respectively (Scheme ) . This reaction was found to proceed stereoselectively, retaining the original configuration of the dipolarophiles.…”

“…was selectively converted into (+)-or (-)-N-Boc-7azabicyclo[2.2.1]heptane-2-one (129). This asymmetric methodology has been suggested to have potential for the enantiospecific synthesis of (+)-and (-)-epibatidine.…”