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A formal [3 + 3] cycloaddition of allenyl imide and activated ketones for the synthesis of tetrasubstituted 2-pyrones.

ABSTRACT: CsOH·H₂O-catalyzed formal [3 + 3] cycloadditions of allenyl imide with β-ketoesters, 1,3-diketones or β-ketonitriles for the synthesis of tetrasubstituted 2-pyrone derivatives have been demonstrated. The allenyl imide was utilized as a C3-synthon, and a ketenyl intermediate was proposed via the process of 1,4-addition of carbon anion to allene followed by elimination of the 2-oxazolidinyl group.

SUBMITTER: Wang YH

PROVIDER: S-EPMC8695344 | biostudies-literature | 2021 Feb

REPOSITORIES: biostudies-literature

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A formal [3 + 3] cycloaddition of allenyl imide and activated ketones for the synthesis of tetrasubstituted 2-pyrones.

Wang Yu-Hao YH Zhang De-Hua DH Cao Ze-Hun ZH Li Wang-Lai WL Huang Yi-Yong YY

RSC advances 20210226 15

CsOH·H<sub>2</sub>O-catalyzed formal [3 + 3] cycloadditions of allenyl imide with β-ketoesters, 1,3-diketones or β-ketonitriles for the synthesis of tetrasubstituted 2-pyrone derivatives have been demonstrated. The allenyl imide was utilized as a C3-synthon, and a ketenyl intermediate was proposed <i>via</i> the process of 1,4-addition of carbon anion to allene followed by elimination of the 2-oxazolidinyl group. ...[more]

PMID: 35423364

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