Department of Chemistry, Faculty of Engineering & Technology, Veer Bahadur Singh Purvanchal University, Jaunpur-222 003, Uttar Pradesh, India Department of Chemistry, University of Texas-Pan American,1201 W. University Dr., Edinburg, TX 78539, USA The University of Texas M. D. Anderson Cancer Center, Department of Molecular Pathology, 1515 Holcombe Blvd, Houston, TX 77030, USA Community Health System of South Texas, 3135 South Sugar Road, Edinburg, TX 78539, USA E-mail: bimalbanik10@gmail.com, bimal.banik@chsst.org Manuscript received 04 October 2018, accepted 02 November 2018 Microwave-induced racemic and asymmetric synthesis of trans acetoxy β-lactams is performed following a nucleophilic substitution reaction of cis 3-mesyl β-lactams with sodium acetate. This method is applicable to obtain a few unusual stereodefined trans acetoxy β-lactams.