Reviews and Accounts
ARKIVOC 2016 (i) 111-149
Chemistry of 3-carbonyl-2-methyl-4-oxo-4H-1-benzopyrans Chandra Kanta Ghosh*a and Amarnath Chakrabortyb a
Organic Chemistry Laboratory, Department of Biochemistry, Calcutta University Kolkata 700 019, India b Department of Basic Sciences and Humanities, Institute of Engineering & Management Salt Lake Electronics Complex, Sector-5, Kolkata 700 091, India Email:
[email protected] DOI: http://dx.doi.org/10.3998/ark.5550190.p009.449 Abstract The review article gives a comprehensive survey of the synthesis and chemistry of the title benzopyrans covering the literature published during 1980 – August 2015. Keywords: Chromones, acylation, Michael addition, [6+0]cyclization, radical cyclization, metal complex formation
Table of Contents 1. 2.
3.
4.
Introduction Synthesis 2.1 Synthesis of 3-formyl-2-methylchromone 1 2.2 Synthesis of 3-acetyl-2-methylchromone 2 2.3 Synthesis of 3-benzoyl-2-methylchromone 3 2.4 Synthesis of 3-hydroxycarbonyl- and 3-alkoxycarbonyl-2-methylchromone 4 and 5 Conjugate Addition to the Pyran 2,3-Olefinic Bond of Chromones without Pyran Ring Opening 3.1 Conjugate reduction 3.2 Conjugate addition of alkyl and alkoxy groups Conjugate Addition with Other Concomitant Reactions 4.1 Addition of ammonia and amines 4.2 Addition of nitrogenous dinucleophiles 4.2.1 Dinucleophiles having adjacent nucleophilic centres 4.2.2 Dinucleophiles with two nucleophilic centres separated by one carbon 4.2.3 Dinucleophiles with two nucleophilic centres separated by two carbons
Page 111
©
ARKAT-USA, Inc.
