“One-pot” access to dihydrofurans via tandem oxidative difunctionalization and ring contraction of aminopyrans

Abstract

An operationally simple and efficient protocol for the construction of dihydrofuran derivatives has been accomplished via a sequential addition of N-chlorosuccinimide and a base to 2-amino-4H-pyran derivatives in alcohol medium. The one-pot protocol proceeding via tandem oxidative difunctionalization and ring contraction provides an entirely new strategy for the construction of the dihydrofuran skeleton.

Dihydronaphthofurans: synthetic strategies and applications

“…The reaction was carried out in CH 2 Cl 2 at room temperature for 12 h yielded 61% of a mixture of cis and trans (20 : 80) 2,3-dihydronaphtho[1,2-b]furan derivatives 28 (Scheme 9). 29 Alla et al 30 noted that one-pot reaction of 2-amino-4H-pyran derivatives 29 with N-chlorosuccinimide and a base (piperidine or aqueous KOH) in alcohol medium at room temperature for 8-9 h gave dihydronaphthofurans 30 in 68-90% yields. Plausible mechanism for the formation of 30 has been arrived at Scheme 10.…”