Premium
Preparation of diastereomeric 5,8‐methanobenzoxazino[2,1–6]‐ and [2,3–6]‐1,3‐benzoxazin‐4‐ones by reaction of norbornane/ene‐condensed dihydro‐1,3‐oxazines with salicyl chloride
Author(s) -
Stájer Géza,
FrimpongManso Samuel,
Bernáth Gábor,
Sohár Pál
Publication year - 1991
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.5570280334
Subject(s) - norbornane , chemistry , diastereomer , norbornene , oxazines , medicinal chemistry , steric effects , chloride , acylation , stereochemistry , organic chemistry , catalysis , polymerization , polymer
Norbornane and norbornene‐condensed dihydro‐1,3‐oxazines 1–6 were converted with salicyl chloride to 5,8‐methanobenzoxazino[2,1–6]‐ and ‐[2,3‐ b ]‐1,3‐benzoxazin‐4‐ones 7–12. The addition takes place to the C N bond: after acylation, the intermediate is stabilized through cyclization to the aryl‐substituted carbon by hydrogen chloride elimination. Diastereomers containing the oxazine rings in isomeric positions could be isolated in two cases. This is the first example of the isolation of diastereomers in such a salicyl chloride reaction. In contrast with earlier findings with reactions of related systems, no addition to the C C bond could be observed. The steric structures of the compounds were elucidated by ir, 1 H‐ and 13 C‐nmr spectroscopy.