Ajinomoto Co., Ltd.

Toagosei Company, Ltd.

Shigeo Nozoe

Tomihisa Ohta

Ken-ichi Tanaka

Akira Takahashi

Kunisuke Izawa

Hiroyuki Izawa

Kuniya Sakurai

Muneaki Kanou

Takashi Ineyama

Hideo Suzuki

Toshiaki Segawa

Sanae Tanaka

Jun-ichi Masuda

Jun-ich Masuda

Antifungal agent

Sesquiterpene compounds

Optically active pyrrolidine derivative

Novel amino acid derivatives of the formula ##STR1## wherein R.sup.1 is a protecting group removable under reducing or acid conditions, and R.sup.2 and R.sup.5 are hydrogen or carboxylic protecting groups, are useful as intermediates in preparing stereospecific carbapenam/carbapenem derivatives. R.sup.1 is removed under reducing conditions to form a pyrrolidine derivative, which is further cyclized from the R.sup.5 =H compound to form a .beta.-lactam ring. Stereospecificity at the 6-position is achieved by treatment with lithium diisopropylamide (LDA) and quenching at different temperatures. Compound (I) can be prepared by treating R.sup.1 -protected R.sup.3 -pyrrolidone carboxylic acid R.sup.2 -ester with a lithium enolate of the formula R.sup.4 CHLiCO.sub.2 R.sup.5. The lithium enolate can be formed from R.sup.4 CH.sub.2 CO.sub.2 R.sup.5 by treatment with LDA.

Process for preparing carbapenem compounds

Novel amino acid derivatives of the formula ##STR1## wherein R.sup.1 is a protecting group removable under reducing or acid conditions, and R.sup.2 and R.sup.5 are hydrogen or carboxylic protecting groups, are useful as intermediates in preparing stereospecific carbapenam/carbapenem derivatives. R.sup.1 is removed under reducing conditions to form a pyrrolidine derivative, which is further cyclized from the R.sup.5 .dbd.H compound to form a .beta.-lactam ring. Stereospecificity at the 6-position is achieved by treatment with lithium diisopropylamide (LDA) and quenching at different temperatures. Compound (I) can be prepared by treating R.sup.1 -protected R.sup.3 -pyrrolidone carboxylic acid R.sup.2 -ester with a lithium enolate of the formula R.sup.4 CHLiCO.sub.2 R.sup.5. The lithium enolate can be formed from R.sup.4 CH.sub.2 CO.sub.2 R.sup.5 by treatment with LDA.

Amino acid derivatives, their production and use in preparing carbapenem

Novel amino acid derivatives of the formula ##STR1## wherein R.sup.1 is a protecting group removable under reducing or acid conditions, and R.sup.2 and R.sup.5 are hydrogen or carboxylic protecting groups, are useful as intermediates in preparing stereospecific carbapenam/carbapenem derivatives. R.sup.1 is removed under reducing conditions to form a pyrrolidine derivative, which is further cyclized from the R.sup.5 .dbd.H compound to form a .beta.-lactam ring. Stereospecificity at the 6-position is achieved by treatment with lithium diisopropylamide (LDA) and quenching at different termperatures. Compound (I) can be prepared by treating R.sup.1 -protected R.sup.3 -pyrrolidone carboxylic acid R.sup.2 -ester with a lithium enolate of the formula R.sup.4 CHLiCO.sub.2 R.sup.5. The lithium enolate can be formed from R.sup.4 CH.sub.2 CO.sub.2 R.sup.5 by treatment with LDA.

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Sendai, Japan

Shigeo Nozoe