Ciba-geigy Corporation

Gerardo Ramos

Peter Schneider

Friedrich Karrer

Alfred Rindlisbacher

Jacques Bersier

Luigi M Venanzi

Hans-Peter Buser

Thomas R Ward

Felix Spindler

Benoit Pugin

Jaroslav Kalvoda

Rene Lattmann

Martin Kessler

The novel 2R,4S-2-ethyl-4-[(4-phenoxyphenoxy)methyl]dioxolan of formula I ##STR1## can be used as a pesticide. It is used to control especially insects in fruit and citrus crops.

Methyldioxolan

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.

Intermediates for the manufacture of 4-acyloxy-3-hydroxyethylazetidinones

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.

Process for the manufacture of 4-acyloxy-3-hydroxyethyl-azetidinones

Compounds of the formula ##STR1## in which R.sub.1 is hydrogen or lower alkyl, R.sub.2 is hydrogen or a hydroxyl protective group R.sub.2 ' and R.sub.3 is substituted or unsubstituted phenyl or lower alkyl can be prepared in a three-stage process from readily accessible .beta.-lactam starting materials.

Process for the preparation of optically active acyloxyazetidinones

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, cyclisation 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.

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.

Process for the manufacture of 4-acylamino-3-hydroxybutyric acid esters

Asymmetric hydrogenation of prochiral N-aliphatic ketimines to give optically active secondary amines at a temperature from -20.degree. to 80.degree. C., a hydrogen pressure of 10.sup.5 to 10.sup.7 Pa, with the addition of catalytic amounts of an iridium compound of the formula III or IIIa

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Arlesheim, Switzerland

Gerardo Ramos