Scholarlink

Abstract <p>A method was developed for the synthesis of 3-nitro-substituted pyrano[3,2-<i>c</i>]chromen-5-ones and thiopyrano[4,3-<i>b</i>]chromen-5-ones from β-nitroenamines and Mannich bases derived from 4-hydroxycoumarin or 4-hydroxythiocoumarin. The reaction represents a cascade process involving the generation of a 1-oxa-1,3-butadiene intermediate, a Diels–Alder reaction with the push-pull β-nitroenamine, and subsequent elimination of a secondary amine.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Synthesis of 3-Nitro-Substituted Pyrano[3,2-c]chromen-5-ones and Thiopyrano[4,3-b]chromen-5-ones

  • 期刊论文

  • 发表日期：

    2025年10月31日

查看全文
  • Dmitry V. Osipov,
  • Anastasia S. Yushkova,
  • Pavel E. Krasnikov,
  • Vitaly A. Osyanin

摘要

Abstract

A method was developed for the synthesis of 3-nitro-substituted pyrano[3,2-c]chromen-5-ones and thiopyrano[4,3-b]chromen-5-ones from β-nitroenamines and Mannich bases derived from 4-hydroxycoumarin or 4-hydroxythiocoumarin. The reaction represents a cascade process involving the generation of a 1-oxa-1,3-butadiene intermediate, a Diels–Alder reaction with the push-pull β-nitroenamine, and subsequent elimination of a secondary amine.