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Ent-Kaurane-based regio- and stereoselective inverse electron demand hetero-Diels-Alder reactions: synthesis of dihydropyran-fused diterpenoids.

ABSTRACT: A mild and concise approach for the construction of a 3,4-dihydro-2H-pyran ring integrated into the A-ring of the natural product oridonin using an optimized inverse electron demand hetero-Diels-Alder (IED HDA) reaction is reported herein. A self-dimerization of the exocyclic enone installed in the A-ring through a homo-HDA reaction was identified to exclusively give a dimeric ent-kaurane diterpenoid with the spirochroman core. Moreover, efficient cross-HDA cycloadditions of this enone with various vinyl ethers or vinyl sulfides, instead of its own homo-HDA dimerization, were achieved in a regio- and stereoselective manner, thus providing access to novel dihydropyran-fused diterpenoids as potential anticancer agents to overcome chemoresistance.

SUBMITTER: Ding C

PROVIDER: S-EPMC4192081 | biostudies-literature | 2014 Nov

REPOSITORIES: biostudies-literature

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ent-Kaurane-based regio- and stereoselective inverse electron demand hetero-Diels-Alder reactions: synthesis of dihydropyran-fused diterpenoids.

Ding Chunyong C Wang Lili L Chen Haijun H Wild Christopher C Ye Na N Ding Ye Y Wang Tianzhi T White Mark A MA Shen Qiang Q Zhou Jia J

Organic & biomolecular chemistry 20141101 42

A mild and concise approach for the construction of a 3,4-dihydro-2H-pyran ring integrated into the A-ring of the natural product oridonin using an optimized inverse electron demand hetero-Diels-Alder (IED HDA) reaction is reported herein. A self-dimerization of the exocyclic enone installed in the A-ring through a homo-HDA reaction was identified to exclusively give a dimeric ent-kaurane diterpenoid with the spirochroman core. Moreover, efficient cross-HDA cycloadditions of this enone with vari ...[more]

PMID: 25225052

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