Nitroalkene [4 + 2] Cycloadditions with 2-(Acyloxy)vinyl Ethers. Stereoselective Synthesis of 3-Hydroxy-4-substituted-pyrrolidines

Scott E Denmark, Mark E. Schnute

Research output: Contribution to journalArticlepeer-review

Abstract

2-(Acyloxy)vinyl ethers undergo regioselective [4 + 2] cycloadditions with nitroalkenes (promoted by SnCl4) to afford substituted 5-acetoxy nitronates in good yields (68–91%). Endo/exo selectivity in the cycloadditions has been found to be dependent on the nitroalkene substitution; 2-aryl-1-nitroalkenes provided exclusively exo cycloadducts while 2-cyclohexyl-1-nitroalkene 28 afforded predominately endo cycloadducts in a ratio of 12:1. The resulting nitronates can be elaborated to N-tosyl-4-substituted-3-hydroxypyrrolidines by hydrogenolysis (160 psi of H2/PtO2) or to bicyclic α-hydroxy lactams by [3 + 2] cycloaddition followed by hydrogenation (14.7 psi of H2/Raney nickel). A chiral 2-acetoxyvinyl ether derived from (R)-2,2-diphenylcyclopentanol has been employed in the cycloaddition‒hydrogenation sequence to prepare an optically active N-tosyl-3-hydroxypyrrolidine in 96% ee.

Original languageEnglish (US)
Pages (from-to)4576-4595
Number of pages20
JournalJournal of Organic Chemistry
Volume59
Issue number16
DOIs
StatePublished - Aug 1 1994

ASJC Scopus subject areas

  • Organic Chemistry

Fingerprint Dive into the research topics of 'Nitroalkene [4 + 2] Cycloadditions with 2-(Acyloxy)vinyl Ethers. Stereoselective Synthesis of 3-Hydroxy-4-substituted-pyrrolidines'. Together they form a unique fingerprint.

Cite this