Kotha S, Solanke BU. Modular Approach to Benzofurans, 2H-Chromenes and Benzoxepines via Claisen Rearrangement and Ring-Closing Metathesis: Access to Phenylpropanoids.
Chem Asian J 2022;
17:e202200084. [PMID:
35218606 DOI:
10.1002/asia.202200084]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 02/25/2022] [Indexed: 11/07/2022]
Abstract
Benzofurans, 2 H -chromenes and benzoxepines are key structural elements present in several natural products and pharmaceuticals. Here, we describe an easy-to-execute strategy for the synthesis of benzofurans, 2 H -chromenes and benzoxepines, by employing Claisen rearrangement and ring-closing metathesis as key steps. A variety of phenols were converted into useful oxacycles in good to excellent yields. The ring-closing metathesis approach has been used to produce phenylpropanoid natural products. Examples described here include, the naturally occurring benzofurans such as 7-methoxywutaifuranal, 7-methoxywutaifuranol, 7-methoxywutaifuranate and the O -prenylated natural products like boropinic acid, boropinols A and C.
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