Asymmetric [4+3] cycloadditions between benzofuranyldiazoacetates and dienes: formal synthesis of (+)-frondosin B.
The reaction of benzofuranyldiazoacetates with 1,3-dienes catalyzed by the dirhodium tetracarboxylate Rh2(R-DOSP)4, generates formal [4+3] cycloadducts with >94% de and 91-98% ee. The reaction proceeds by a tandem cyclopropanation/Cope rearrangement followed by a stereoselective tautomerization. This methodology was extended to a formal synthesis of (+)-frondosin B.
Olson
Jeremy P
JP
Department of Chemistry, University at Buffalo, The State University of New York, Buffalo, New York 14260-3000, USA.
Davies
Huw M L
HM
D000475:Alkenes / Q000737:chemistry*; D001572:Benzofurans / Q000737:chemistry*; D002384:Catalysis; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
D000475:Alkenes; D001572:Benzofurans; D006576:Heterocyclic Compounds, 4 or More Rings; C421322:frondosin B