Tetrahedron

… acid11M. Shiozaki and T. Hiraoka, Tetrahedron Letters 4473 (1980); M. Shiozaki and T. Hiraoka, Tetrahedron 38, 3457 (1982). M. Shiozaki, N. Ishida, T. Hiraoka and …

M Shiozaki, N Ishida, H Maruyama, T Hiraoka

Index: Shiozaki; Ishida; Maruyama; Hiraoka Tetrahedron, 1983 , vol. 39, # 14 p. 2399 - 2407

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Citation Number: 50

Abstract

Stereospecific and stereoselective syntheses of cis-12, and stereoselective synthesis of (±)- trans-12 from D-allo threonine and trans-crotonic acid, respectively, are described. The key steps in the syntheses are the formation of the β-lactam ring (4) by cyclization of the amide (3) via a complete Sn2 mechanism and stereocontrolled conversion of the azetidinone (4) to 12, 13 and 14, which are intermediates for the penems and the carbapenems.