TY - JOUR
T1 - Ester-Imine Condensations
T2 - Preparation of Racemic Intermediates for the Synthesis of the Carbapenem Antibiotics PS-5 and PS-6
AU - Ha, Deok Chan
AU - Hart, David J.
N1 - Copyright:
Copyright 2016 Elsevier B.V., All rights reserved.
PY - 1987
Y1 - 1987
N2 - The lithium enolates of ethyl butyrate (7) and ethyl isovalerate (19) react with N-p-methoxyphenylcinnamaldimine (8) in tetrahydrofuran (THF) - hexamethylphosphoric triamide (HMPA) to afford predominantly trans β-lactams 9 (67 %) and 20 (78 %), respectively. β-Lactam 9 was converted to PS-5 (5) intermediate 18 in 21 % overall yield (8 steps). β-Lactam 20 was converted to PS-6 (6) analog 28 in 22 % overall yield using an eight step sequence.
AB - The lithium enolates of ethyl butyrate (7) and ethyl isovalerate (19) react with N-p-methoxyphenylcinnamaldimine (8) in tetrahydrofuran (THF) - hexamethylphosphoric triamide (HMPA) to afford predominantly trans β-lactams 9 (67 %) and 20 (78 %), respectively. β-Lactam 9 was converted to PS-5 (5) intermediate 18 in 21 % overall yield (8 steps). β-Lactam 20 was converted to PS-6 (6) analog 28 in 22 % overall yield using an eight step sequence.
UR - http://www.scopus.com/inward/record.url?scp=0023113036&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0023113036&partnerID=8YFLogxK
U2 - 10.7164/antibiotics.40.309
DO - 10.7164/antibiotics.40.309
M3 - Article
C2 - 3570984
AN - SCOPUS:0023113036
VL - 40
SP - 309
EP - 319
JO - Journal of Antibiotics
JF - Journal of Antibiotics
SN - 0021-8820
IS - 3
ER -