Abstract
Synthesis of highly strained fused substituted dihydrobenzopyran cyclopropyl lactones derived from coumarin carboxylates are reported. The substrate scope tolerates a variety of 6- and 8-substituents on the coumarin ring. Substitution at the 5- or 7-position is resistant to tricyclic lactone formation except with 7-methyl substitution. Benzamide-containing coumarins afford the tricyclic ketal. A plausible mechanism is proposed for the formation of the fused lactone: intramolecular rearrangement of trans cyclopropyl methyl ketones with phenolic acetate via the formation of a hemiacetal.
Original language | English (US) |
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Pages (from-to) | 4476-4482 |
Number of pages | 7 |
Journal | Journal of Organic Chemistry |
Volume | 87 |
Issue number | 6 |
DOIs | |
State | Published - Mar 18 2022 |
ASJC Scopus subject areas
- Organic Chemistry