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Diethylborylierung und Sulfidierung von ω‐Lactamen
Author(s) -
Köster Roland,
Kucznierz Ralf,
Schüßler Wilhelm,
Bläser Dieter,
Boese Roland
Publication year - 1993
Publication title -
liebigs annalen der chemie
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0170-2041
DOI - 10.1002/jlac.199319930134
Subject(s) - chemistry , conformational isomerism , thermal decomposition , monomer , yield (engineering) , stereochemistry , decomposition , medicinal chemistry , crystallography , molecule , organic chemistry , polymer , materials science , metallurgy
Diethylborylation and Sulfidation of ω‐Lactams Several reaction modes of ω‐lactams [ A ( n = 3), B (4), C (5), D (6), E (7), F (11)] with Et 3 B are observed between 20 and 110°C. The Et 2 B lactims ( 1 ) having various degrees of association [( 1a ) x ; 1b ; ( 1d ) 2 (X‐ray structure); 1e ; ( 1f ) 4 ] are formed by elimination of 1 mol of ethane. The condensation products [ 2b ; 2c (X‐ray structure)] result by elimination of 1.33 mol of ethane together with the lactim derivatives ( 3b ; 3c ). Thermolysis (≥ 125°C) of ( 1d ) 2 , 1e , and ( 1f ) 4 leads to mixtures, in which the compounds 2d, e, f and 3d, e, f , resp., have been identified (NMR, MS). Differences of the thermal behaviour of 1a – f ( s‐cis/trans conformers, cis/trans lactims, association degree) are discussed. – From 2b, c and Hacac the N ‐acylamidines ( 4b, c ) are obtained, which react with (9‐BBN) 2 S to yield the monomeric 9‐BBN‐ω‐thiolactims [ 5b ; 5c (X‐ray structure)]. The latter react with MeOH to give the ω‐thiolactams ( 6b, c ) and 9‐MeO‐9‐BBN, from which the 2:2 MeOH addition compound ( 7 ) 2 (X‐ray structure) is obtained.