195524-03-9Relevant academic research and scientific papers
Structural features in the seven-membered vs. Fourteen-membered ring cyclization of hydroxyamido ketals derived from β-amino alcohols
Valade, Anne-Gaelle,Dugat, Denise,Jeminet, Georges,Royer, Jacques,Husson, Henri-Philippe
, p. 2041 - 2053 (2007/10/03)
Hydroxyamido ketals 1 and 3-12, prepared from β-amino alcohols, are obtained either as a single form with a trans (1 and 3-8) or cis (9) conformation in the R = H series or as two cis and trans rotamers in the R ≠ H series (10-12). - The cyclization of these compounds was studied under acidic conditions (PTSA) and over a well defined range of concentrations (c = 0.1-0.2 M). While cis amide 9 and mixtures of cis and trans rotamers 10-12 resulted practically exclusively in the formation of seven-membered ring lactams 22-25, trans compounds 1 and 3-8 afforded fourteen-membered ring bislactams 2, 13-18, the formation of which involves a dimerization. Macrocycles were obtained as three diastereomers in the chiral series 2, 13-16 and as two isomers in the achiral series 17 and 18. Nineteen macrocyclic bislactams have thus been synthesized.
A new and rapid access to a 14-membered diketal dilactam ring
Dugat, Denise,Chiaroni, Angele,Riche, Claude,Royer, Jacques,Husson, Henri-Philippe
, p. 5801 - 5804 (2007/10/03)
Macrocyclic dioxadilactam 2 was obtained in two steps from R-(-)-phenylglycinol via the chiral amido-ketal 1. Cyclization of 1 in acidic conditions (PTSA) and concentrated solution (9 = 0.15 M) afforded 2 as three diasteromers 2a+2b+2c, two of which show a C-2 symmetry.
