Synlett 2019; 30(03): 293-298
DOI: 10.1055/s-0037-1611706
letter
© Georg Thieme Verlag Stuttgart · New York

Molecular-Iodine-Promoted Synthesis of Dihydrobenzofuran-3,3-dicarbonitriles through a Novel Rearrangement

Nagaraju Medishetti
a   Fluoro & Agro Chemicals Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
c   AcSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India   Email: krishnu@iict.res.in
,
Ashok Kale
a   Fluoro & Agro Chemicals Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
c   AcSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India   Email: krishnu@iict.res.in
,
Jagadeesh Babu Nanubolu
b   Laboratory of X-ray Crystallography, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
,
a   Fluoro & Agro Chemicals Division, CSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
c   AcSIR-Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India   Email: krishnu@iict.res.in
› Author Affiliations
We are grateful to SERB-DST, New Delhi, for financial support (Grant no. EEQ/20l6/000066). We gratefully acknowledge the help received from the Centre for NMR & Structural Chemistry and Analytical Chemistry & Mass Spectrometry, CSIR –IICT.
Further Information

Publication History

Received: 01 November 2018

Accepted after revision: 16 December 2018

Publication Date:
11 January 2019 (online)


CSIR-IICT Communication No. IICT/pubs./2018/203.

Abstract

The title compounds were synthesized from 5,5-dimethyl­cyclohexane-1,3-dione, benzaldehyde, and malononitrile promoted by molecular iodine in basic medium via 2-amino-7,7-dimethyl-5-oxo-4-phenyl-5,6,7,8-tetrahydro-4H-chromene-3-carbonitrile, by a novel protocol. The protocol involves a novel rearrangement in which the 4H-chromene fragment dissociates to a cyclopropane moiety and rearranges to the five-membered compound 6,6-dimethyl-4-oxo-2-phenyl-4,5,6,7-tetrahydrobenzofuran-3,3(2H)-dicarbonitrile. Simple reaction conditions, excellent yields, and high compatibility are the advantages of this protocol.

Supporting Information