Diastereoselective Construction of Spirocyclic Isobenzofurans via a Tandem Michael Addition/5-Exo-dig Cyclization
Shaghayegh Mehdidoust1, Saideh Rajai-Daryasarei1, S Sina Hosseini1
1Peptide Chemistry Research Institute, K. N. Toosi University of Technology, P.O. Box 15875-4416, Tehran 15418-49611, Iran.
Abstract:
A practical approach for rapid and efficient access to spirocyclic isobenzofurans is described. The reaction proceeds through the cycloaddition of 1,6-ynenone derivatives and 4-nitro-1,3-diarylbutan-1-ones, promoted by Cs2CO3 in the presence of l-proline as a catalyst. The advantages of this reaction include the formation of two C-C bonds and one C-O bond as well as mild reaction conditions. Extended spirocyclic isobenzofurans are obtained with good efficiency and diastereoselectivity under these mild conditions, and this new protocol avoids the use of any transition-metal reagents.
Related Concept Videos
Cyclohexenones via Michael Addition and Aldol Condensation: The Robinson Annulation
Cycloaddition Reactions: Overview
Diels–Alder Reaction Forming Bridged Bicyclic Products: Stereochemistry
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Cycloaddition Reactions: MO Requirements for Thermal Activation

![Solid-phase Synthesis of [4.4] Spirocyclic Oximes](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F58508.jpg&w=3840&q=50)
