Abstract: A process for preparing azetidinones of the formulae 1 and 2A and the stereoisomers of the latter of formula 2B ##STR1## wherein R is an amino-protecting group commonly used in penicillin chemistry and is selected from the group consisting of H, C.sub.1 -C.sub.6 alkyl, phenyl, (optionally substituted in the o-, m-, or p- positions by CH.sub.3, F, Cl, OCH.sub.3, or a nitro group), benzyl, 2-thienylmethyl, tetrazol (1-, 2-, or 5-)-ylmethyl, 2-phenyl-5-methylisoxazol-4-yl, phenoxymethyl, and R.sup.5 O-- and R.sup.5 S, wherein R.sup.5 stands for C.sub.1 -C.sub.6 alkyl, phenyl, benzyl or trichloroethyl; it should be noted that the value of R is immaterial to the process described;X is selected from the group consisting of H, SCl, SBr, Cl, Br, and OH. In the case where X is OH the group RCX.dbd.N-- is better represented as the amide, RCONH--, group;RCX.dbd.N may also represent the phthalimido, succinimido-, or tritylamino- group;R.sup.

Abstract: A process for preparing 2-acyloxymethylpenams and 3-acyloxycephams of the formulae 1 and 2 ##STR1## in which R represents the aliphatic, aromatic, or heterocyclic moiety of an amino-protecting group commonly employed in penicillin chemistry, R.sup.1 is hydrogen or represents a carboxy-protecting group commonly employed in penicillin chemistry, and R.sup.2 is hydrogen, C.sub.1 -C.sub.6 alkyl which may also be substituted with Cl, OCH.sub.3, or CN, and phenyl which may also be substituted with CH.sub.3, F, Cl, OCH.sub.3 or NO.sub.2, by treating an unsym-azetidinone disulfide of the formula 3 ##STR2## in which R and R.sup.1 are as defined above and R.sup.4 is benzothiazol-2-yl or benzoxazol-2-yl with silver oxide, an acid of the formula R.sup.2 COOH, and iodine, or with a silver salt of the formula R.sup.2 COOAg and iodine, or with a Simonini complex of the formula R.sup.2 COOI.R.sup.2 COOAg, to obtain a mixture of the compounds of formulae 1 and 2, and optionally separating said mixture.

Abstract: Thiazolineazetidinone derivatives of the formulae 1,2, and 3. ##STR1## wherein R is derived from the commonly known carboxamido groups present in penicillins, R.sup.1 is a carboxy protecting group commonly used in penicillin chemistry, and R.sup.2 is Cl, Br, I, CN, lower alkoxy, lower acyloxy, SCN, SCH.sub.3, S-phenyl, S-heteroaryl such as 5-mercaptotetrazole or 2-mercapto-5-methyl-1,3,4-thiadiazole, NO.sub.3, N.sub.3, NH-phenyl, and N(CH.sub.3).sub.2 with the proviso that R.sup.2 in the compounds of formula 1 is limited to Cl, Br, I, and lower acyloxy, and a process for preparing said compounds from 2-(substituted methyl) penicillin sulfoxides followed by treatment with a base.The compounds of formulae 1,2, and 3 are useful as intermediates in the synthesis of cephalosporins.

Abstract: Novel 2-iodomethyl-penicillanic acid derivatives are prepared and are useful for the preparation of bioactive 2,3-methylenepenams and 2-methylceph-3-ems.

Abstract: An improved process for preparing 4-thia-2,6-diazabicyclo[3,2,0]hept-2-ene-7-ones such as methyl 3-phenoxy-4-thia-2,6-diazabicyclo[3,2,0]hept-2-ene-7-one-6-isopropenylacet ate which comprises extruding sulfur from dithiazeneazetidinones such as methyl 3-phenoxymethyl-4,5-dithia-2,7-diazabicyclo[4,2,0]-oct-2-ene-8-one-7-isopr openylacetate. The compounds obtained are useful intermediates in the preparation of certain 3-cephems.

Abstract: The invention relates to novel azetidinones of the general formula: ##STR1## wherein R stands for lower alkyl, phenyl, phenyloxyloweralkyl, phenylloweralkyl, 2-thiophenemethyl, 5-tetrazolylmethyl, R.sup.3 O--and R.sup.3 S--, wherein R.sup.3 stands for lower alkyl, phenyl or phenylloweralkyl; R.sup.1 is hydrogen or a cleavable radical selected from lower alkyl; loweralkoxymethyl, 2,2,2-trichloroethyl, benzyl, p-halobenzyl, p-nitrobenzyl and p-methoxybenzyl, benzhydryl and trimethylsilyl; R.sup.2 is hydrogen or methoxy; X is SCl, Sbr or --OH in which case the C.sub.3 -sidechain is better represented as the amide RCONH-- group; Y is chloro or bromo; and ##STR2## may also be taken as phthalimido. These novel compounds possess antibacterial activity and are useful intermediates for the synthesis of modified penicillins and the analogues of penicillins.

Abstract: The invention relates to compounds of the formula: ##STR1## wherein R stands for lower alkyl, aryl, heteroaryl, benzyl, heteroarylloweralkyl, phenoxyloweralkyl, phenylthioloweralkyl, 4-amino-1-butyl and suitably protected derivatives, .alpha.-aminobenzyl and protected derivatives such as the carbamates (benzyl, trichloroethyl and methoxymethyl) and aldehyde and ketone adducts, .alpha.-hydroxybenzyl and protected derivatives, .alpha.-carboxybenzyl and protected derivatives, .alpha.-sulfobenzyl and protected derivatives, the radical R.sup.5 O--, R.sup.5 S--, or R.sup.5 R.sup.6 N--,wherein R.sup.5 and R.sup.6 may be the same or different and each be taken from the group lower alkyl, aryl, arylloweralkyl and heteroaryl and additionally, in the case of R.sup.5 R.sup.6 N--, R.sup.5 and/or R.sup.6 may be hydrogen;R.sup.

Abstract: The invention relates to compounds of the formula: ##STR1## wherein R stands forBenzyl,Phenoxymethyl,4-amino-4-carboxy-1-butyl,R.sup.3 o--, r.sup.3 s--, r.sup.3 r.sup.4 n-- whereinR.sup.3 is loweralkyl, aryl or arylloweralkyl,R.sup.4 is hydrogen or R.sup.3, andR.sup.2 is hydrogen or methoxy, andR.sup.1 is hydrogen or a cleavable radical such as--CH.sub.2 OCH.sub.3, loweralkyl, 2,2,2-trichloroethyl, benzyl, p-nitrobenzyl, benzhydryl, phenacyl or trimethylsilyl. The novel compounds are useful intermediates in the preparation of known penicillin and cephalosporin derivatives.

Abstract: The invention relates to compounds of the formula: ##STR1## wherein R stands for benzyl, phenoxymethyl, 4-amino-4-carboxy-1-butyl, R.sup.3 O--, R.sup.3 S--, R.sup.3 R.sup.4 N-- wherein R.sup.3 is loweralkyl, aryl or arylloweralkyl, R.sup.4 is hydrogen or R.sup.3, and OH when the radicals R.sup.3 O--, R.sup.3 S-- and R.sup.3 R.sup.4 N--are hydrolyzed; R.sup. 2 is hydrogen or methoxy, and R.sup.1 is hydrogen or a cleavable radical such as --CH.sub.2 OCH.sub.3, loweralkyl, 2,2,2-trichloroethyl, benzyl, p-nitrobenzyl, benzhydryl, phenoxyethyl or trimethylsilyl. The novel compounds are useful intermediates in the preparation of known penicillin and cephalosporin derivatives.