Abstract
A straightforward and industrially feasible synthesis of 7β-acylamino-7α-methoxy-3- [(1-methyl-1
H
-tetrazol-5-ylthio)methyl]-1-oxa-3-cephem-4-carboxylic acid (35) from penicillins is described. Reaction of 6α-acylaminopenicillanate
S
-oxides with triphenylphosphine gave epioxazolines (16) which were transformed into allylic alcohols (28) via allylic chlorides (22) and iodides (27). Intramolecular etherification of 28 gave 7α-acylamino-3-exomethylene-1-oxacepham-4α-carboxylate (30), a versatile key intermediate. 7α-Methoxylation of 30, followed by substitution with sodium 1-methyl-1
H
-tetrazol-5-ylthiolate at C
3
and side chain cleavage, afforded the methoxyamine (33), the desired 1-oxa-3-cephem nucleus, which on acylation and subsequent deprotection gave 35 (6059-S free acid, where the acyl is
p
-hydroxyphenylmalonyl).
Subject
Industrial and Manufacturing Engineering,General Agricultural and Biological Sciences,General Business, Management and Accounting,Materials Science (miscellaneous),Business and International Management
Cited by
16 articles.
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