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A new regioselective synthesis of 2,3,4,5‐tetrahydro‐6 H ‐oxepino[3,2‐ c ]pyran‐6‐ones, and [1]benzopyran‐6‐ones
Author(s) -
Bravo Pierfrancesco,
Frigerio Massimo,
Ticozzi Calimero
Publication year - 1988
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570250252
Subject(s) - chemistry , regioselectivity , benzopyran , pyran , intramolecular force , olefin fiber , toluene , dehydration , medicinal chemistry , organic chemistry , boiling , catalysis , biochemistry
Through an anti‐Markovnikow hydration of some olefin derivatives of 4‐hydroxy‐2‐pyrones, and 4‐hydroxy‐coumarins, followed by a regioselective intramolecular dehydration, involving the primary alcohols obtained and the enolic oxygen of the rings, promoted by Amberlyst 15 in boiling toluene, the new heterocycles 2,3,4,5‐tetrahydro‐6 H ‐oxepino[3,2‐ c ]pyran‐6‐one ( 3 ) and [1]benzopyran‐6‐ones ba,c were obtained in fair yields.