Synthesis of novel 2H,8H-pyrano[2,3-f]chromene-2,8-diones from 8-formyl-7-hydroxy-4-methylcoumarin
β Scribed by Al-Kawkabani, Ahmed; Boutemeur-Kheddis, Baya; Makhloufi-Chebli, Malika; Hamdi, Maamar; Talhi, Oualid; Silva, Artur M.S.
- Book ID
- 120535155
- Publisher
- Elsevier Science
- Year
- 2013
- Tongue
- French
- Weight
- 369 KB
- Volume
- 54
- Category
- Article
- ISSN
- 0040-4039
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π SIMILAR VOLUMES
A concise synthesis of 5-hydroxy-2,2-dimethyl-10-propyl-2H-pyrano[2,3-f ]chromen-8-one utilising a novel selective desulfonylation protocol is described. This method provides facile access to a key intermediate for the asymmetric synthesis of calanolide A.
## Abstract 7β(Methoxyimino)β4βmethylβ2__H__βchromeneβ2,8(7__H__)βdione (3) reacts with phosphonium salts 1aβc, 8a, b under phasetransfer catalysis conditions to afford the title 2βsubstituted 6βmethylbenzopyranooxazolβ8βones 5aβc, 10a, b, respectively, along with compound 6, instead of the expecte