Premium
Ring transformations of heterocyclic compounds. XX Benzo‐fused spiro[cyclohexadiene‐dihydroindoles] by ring transformation of pyrylium salts with anhydrobases of benzo[ e ]‐ and benzo[ g ]indolium salts
Author(s) -
Zimmermann Thomas
Publication year - 2000
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.5570370435
Subject(s) - chemistry , ring (chemistry) , medicinal chemistry , acetic acid , stereochemistry , triethylamine , methylene , organic chemistry
The diastereoselective synthesis of 6‐aroyl‐3,5‐diarylspiro[cyclohexa‐2,4‐diene‐1,2′2′,3′‐dihydro‐1′ H ‐benzo[e]indoles] 6 and ‐benzo[ g ]indoles] 7 from 2,4,6‐triarylpyrylium perchlorates 1 and in situ generated 2‐methylene‐2,3‐dihydro‐1 H ‐benzo[ e ]indoles 3 or ‐benzo[ g ]indoles 5 (anhydrobases of the corresponding 2‐methyl‐1 H ‐benzo[ e ]indolium perchlorates 2 and 2‐methyl‐3 H ‐benzo[ g ]indolium perchlorates 4 , respectively) in the presence of triethylamine/acetic acid in ethanol by a 2,5‐[C 4 +C 2 ] pyrylium ring transformation is reported. Spectroscopic data of the transformation products and their mode of formation are discussed.