Abstract: The invention relates to a novel process for the manufacture of 4-acetoxy-3-hydroxyethyl-azetidinone of the formula ##STR1## especially 4(R)-acetoxy-3(R)-(1'(R)-hydroxyethyl)-2-azetidinone, from enantiomerically pure compounds of the formula ##STR2## in which R.sup.1 represents lower alkyl and Z.sup.1 represents amino, arylmethylamino, acylamino or azido, by reduction of the C.dbd.C double bond and optionally of the arylmethylamino or azido group with hydrogen, opening of the lactone ring, cyclisation to the .beta.-lactam, optionally after hydrolysis of the acylamino group, and oxidative decarboxylation of the original lactone carboxy group in the presence of an acetate-yielding agent. Compounds of the formula I can be used as starting materials for the manufacture of .beta.-lactam antibiotics. The invention also relates to novel intermediates and starting materials.

Abstract: The invention relates to the 3-(1'-hydroxyethyl)-2-azetidinone of formula ##STR1## which can be transformed into 4-acyloxy-3-(1-hydroxyethyl)-2-azetidinone derivatives. The latter can be used as starting materials for the manufacture of a large number of highly active .beta.-lactam antibiotics.

Abstract: The invention relates to a novel process for the manufacture of 4-acetoxy-3-hydroxyethyl-azetidinone of the formula ##STR1## especially 4(R)-acetoxy-3(R)-(1'(R)-hydroxyethyl)-2-azetidinone, from enantiomerically pure compounds of the formula ##STR2## in which R.sup.1 represents lower alkyl and Z.sup.1 represents amino, arylmethylamino, acylamino or azido, by reduction of the C.dbd.C double bond and optionally of the arylmethylamino or azido group with hydrogen, epimerization, opening of the lactone ring, cyclisation to the .beta.-lactam, optionally after hydrolysis of the acylamino group, and oxidative decarboxylation of the original lactone carboxy group in the presence of an acetate-yielding agent. Compounds of the formula I can be used as starting materials for the manufacture of .beta.-lactam antibiotics. The invention also relates to novel intermediates and starting materials.

Abstract: A process for the manufacture of a compound of the formula IIIa ##STR1## wherein R.sup.2 is lower alkyl and R.sup.3 is lower alkanoyl or arylcarbonyl comprising reducing a compound of formula II ##STR2## wherein R.sup.2 is lower alkyl and R.sup.3 is lower alkanoyl or arylcarbonyl or a salt thereof with Saccharomyces cerevisiae.

Abstract: The invention relates to a novel process for the manufacture of (3R,1'R)-4-acyloxy-3-(1'-hydroxyethyl)-2-azetidinones of formula ##STR1## in which R.sup.1 represents lower alkyl or aryl, by enantioselective reduction of the carbonyl group in a suitable .alpha.-acylaminomethyl-acetoacetic acid ester, cyclization of the resulting .alpha.-acylaminomethyl-.beta.-hydroxybutyric acid ester to a 5,6-dihydro-1,3,4H-oxazine with inversion of the carbon atom carrying the hydroxy group, equilibration to form the preferred trans-substituted dihydrooxazine, recleaving to form the configuratively uniform .alpha.-aminomethyl-.beta.-hydroxybutyric acid, ring-closure to form the .beta.-lactam and oxidative acylation at C(4) of the .beta.-lactam. Compounds of formula I can be used as starting materials for the manufacture of .beta.-lactam antibiotics. The invention relates also to novel intermediates.

Abstract: The invention describes a process for the production of benzanthrone by reacting anthraquinone with glycerol and/or acrolein, using anthrone as reducing agent.Benzanthrone is an important intermediate for dyes and is used in particular for the preparation of vat dyes.

Abstract: An electrochemical process for the preparation of benzanthrones and planar, polycyclic aromatic oxygen-containing compounds is described. The process is carried out in an acid medium in an electrolytic cell which is separated by a diaphragm into a cathode compartment and an anode compartment.In the cathode compartment, anthraquinone or an anthraquinone derivative is reduced electrolytically to oxanthrone and the latter is reacted with glycerol to give the corresponding benzanthrone.In the anode compartment, a transition metal ion is simultaneously converted electrolytically from a lower oxidation stage into the next higher oxidation stage. The metal ion of higher valency is then used in the anolyte as an oxidizing agent by means of which the corresponding oxygen-containing compounds are obtained, starting from planar, polycyclic aromatic compounds.

Abstract: An electrochemical process for the production of benzanthrone by reaction of anthraquinone as, starting material, with glycerol, which process comprises reducing anthraquinone, which may additionally contain electronegative substituents, at the cathode in an electrolytic cell in acid medium, and simultaneously cyclizing the reduced semiquinone form with glycerol to produce the corresponding benzanthrone. The novel process affords numerous advantages compared with chemical reduction methods.