Work

An Optically Active 4‐Aryl‐3,4‐dihydroisocoumarin‐3‐carboxylate

Year: 2024

Type: article

Abstract: A four step sequence for the preparation of optically active (R,R)‐ethyl 4‐phenyl‐3,4‐dihydroisocoumarin‐3‐carboxylate is reported. In the first step the first stereocenter was installed by palladium catalyzed asymmetric conjugate addition of PhB(OH)2 to indenone (88 % ee). After deprotonation, the ester moiety was introduced with Mander's reagent. The α‐hydroxylation of the resulting β‐oxoester was then achieved with cerium‐catalysis under an air atmosphere. Key transformation was the cyanide‐catalyzed ring transformation of α‐hydroxy‐β‐oxoester furnishing the δ‐lactone moiety of the target compound, which was formed as a mixture of separable cis‐ and trans‐diastereoisomers, both with 88 % ee. The cis‐isomer could be epimerized to the trans‐compound. The relative trans and the absolute (R,R)‐configuration of the target compound was established by X‐ray single crystal structure analysis.

Source: European Journal of Organic Chemistry

DOI: 10.1002/ejoc.202400769

Authors: Oliver Groben, Marc Schmidtmann, Jens Christoffers

Institution: Carl von Ossietzky Universität Oldenburg

Language: English

Topic: Asymmetric Synthesis and Catalysis

Subfield: Organic Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,330

Funder: Deutsche Forschungsgemeinschaft