NaHSO₄–SiO₂-catalyzed aza-Diels–Alder reaction of o-hydroxybenzaldimines with 2,3-dihydrofuran: Diastereoselective synthesis of furanobenzopyrans

ABSTRACT

NaHSO₄ supported on silica gel catalyzes the aza-Diels–Alder reaction of o-hydroxybenzaldimines with 2,3-dihydrofuran to provide furanobenzopyrans in reasonable yields and diastereoselectivity. The catalyst is recyclable and reusable up to two times without a significant loss of activity.

GRAPHICAL ABSTRACT

KEYWORDS:

• Aza-Diels–Alder
• furanobenzopyrans
• NaHSO₄–SiO₂
• Povarov reaction

Additional information

Funding

This work was supported by the National Research Foundation [Grant Number 93614] and Sasol [Grant Number 275520].