Helvetica chimica acta

Asymmetric Synthesis of Diazepino?螃漫?lactams by [2+ 2] Cycloaddition of an 'Evans??Sjogven'Ketene with 1H??1, 2??Diazepines

M Muller, D Bur, T Tschamber…

Index: Muller, Marc; Bur, Daniel; Tschamber, Theophile; Streith, Jacques Helvetica Chimica Acta, 1991 , vol. 74, # 4 p. 767 - 773

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Citation Number: 16

Abstract

Abstract The ketene derivative of the chiral oxazolidinone 1 underwent non-concerted stereo specific [2+ 2] cycloadditions with the (Z)-imine moiety of diazepines 2, leading thereby with good diastereoselection to the trans-β-lactam adducts 3 (major) and 4 (minor). The absolute configuration of the major cycloadduct 3a was determined by an X-ray analysis. Its formation is discussed in terms of minimisation of steric interaction in the two transition states which ...