Schering Corporation

Xing Chen

Yee-Shing Wong

Guang-Zhong Wu

Martin Steinman

Doris P Schumacher

Marc Poirier

George G Wu

The invention relates to intermediates of the formulae ##STR1## said intermediates being useful in a process for producing a compound of the formula ##STR2## wherein Bn is benzyl and R.sub.1, .sub.2 and R.sub.3 are as defined in the specification,

3-hydroxy gamma-lactone based enantioselective synthesis of azetidinones

The invention relates to a process for preparing a compound of the formula ##STR1## comprising reacting a bromo-substituted pyridine with an amine of the formula NHR.sup.5 R.sup.6, reacting the resulting amide with an iodo-halomethyl-substituted compound and cyclizing the resultant product, wherein R, R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are as defined in the specification; also claimed are a compound of the formula ##STR2## and a process for preparing it from the corresponding halo-substituted benzoic acid.

Synthesis of intermediates useful in preparing tricyclic compounds

The invention relates to a process for producing a compound of the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are as defined in the specification, which comprises the steps of: (a) reacting a lactone with an imine to obtain a chiral diol of the formula IV; (b) oxidizing the diol to obtain an aldehyde of formula V; (c) condensing the aldehyde with an enolether followed by dehydration to obtain a compound of formula VI; (d) hydrogenating the compound of formula VI to obtain a ketone of formula VII; and (e) chirally catalytically reducing the ketone, wherein steps (b)-(d) are shown in the following reaction scheme: ##STR2##

The invention relates to a process for preparing a compound of the formula ##STR1## comprising: (a) reacting 2,5-dibromo-3-methylpyridine with an amine of the formula NHR.sup.5 R.sup.6 to obtain an amide;

Synthesis of intermediates useful in preparing bromo-substituted

The invention relates to a process for producing the compound of the formula ##STR1## which comprises reacting lactone of formula II ##STR2## with an imine of formula III': ##STR3## and converting the resulting chiral diol of formula VI: ##STR4## through several steps to obtain a compound of formula I'.

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Plainsboro, NJ, United States of America

Xing Chen