A novel two-carbon homologation with N-vinylacetamides and ethyl vinyl ether as acetaldehyde anion equivalents in the synthesis of 9H-xanthene, 9H-thioxanthene, and 9,10-dihydro-9-acridine carboxaldehydes.
An efficient synthesis of 9H-xanthene-9-carboxaldehyde (3a), 9H-thioxanthene-9-carboxaldehyde (3b), and 9,10-dihydro-10-methyl-9-acridinecarboxaldehyde (3c) by a novel two-carbon homologation of xanthydrol (1a), thioxanthydrol (1b), and 9,10-dihydro-10-methyl-9-acridinol (1c), respectively, using N-vinylacetamides (2a,b) or ethyl vinyl ether (2c) as acetaldehyde anion equivalents, is described.
Prashad
Mahavir
M
Process Research and Development, Chemical and Analytical Development, Novartis Institute for Biomedical Research, One Health Plaza, East Hanover, New Jersey 07936, USA. mahavir.prashad@pharma.novartis.com
Lu
Yansong
Y
Repic
Oljan
O