TY - JOUR
T1 - Penicillin-cephalosporin conversion. VII. An improved synthesis of 3-methylenecephams
AU - Torii, S.
AU - Tanaka, H.
AU - Siroi, T.
PY - 1983/1/1
Y1 - 1983/1/1
N2 - Efficient conversion of 2-(7-oxo-2,6-diaza-4-thiabicyclo left bracket 3. 2. 0 right bracket hept-2-en-6-yl)-3-chloromethyl-3-butenoates (4), derived from natural pencillins, into 3-methylenecephams (1) has been performed by a simple two-step operation, which comprises replacement of the allylic chlorine atom of 4 with iodine and subsequent acid-catalyzed hydrolysis, leading to 1 in 70-54% overall yields. In the latter step, the ring opening of the thiazoline moiety and the intramolecular substitution of the iodide with the thiol group proceed simultaneously.
AB - Efficient conversion of 2-(7-oxo-2,6-diaza-4-thiabicyclo left bracket 3. 2. 0 right bracket hept-2-en-6-yl)-3-chloromethyl-3-butenoates (4), derived from natural pencillins, into 3-methylenecephams (1) has been performed by a simple two-step operation, which comprises replacement of the allylic chlorine atom of 4 with iodine and subsequent acid-catalyzed hydrolysis, leading to 1 in 70-54% overall yields. In the latter step, the ring opening of the thiazoline moiety and the intramolecular substitution of the iodide with the thiol group proceed simultaneously.
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U2 - 10.1246/bcsj.56.1567
DO - 10.1246/bcsj.56.1567
M3 - Article
AN - SCOPUS:0020759140
SN - 0009-2673
VL - 56
SP - 1567
EP - 1568
JO - Bulletin of the Chemical Society of Japan
JF - Bulletin of the Chemical Society of Japan
IS - 5
ER -