[2H5]‐Amprenavir and [2H 5]‐saquinavir have been prepared from a common labeled precursor (1S, 2S)‐(1‐oxiranyl‐2‐[2H5]phenylethyl)‐carbamic acid tert‐butyl ester, 1. Both of these compounds are in the ‘HEA’ class of HIV protease inhibitors. [2H5]‐Indinavir, a representative of the ‘HEE’ group of protease inhibitors, has also been synthesized. In the case of indinavir, 1S‐(2,2‐dimethyl‐8, 8a‐dihydro‐3aH‐indeno‐[1,2‐d]‐oxazol‐3R‐yl)‐2‐oxiranylmethyl‐3‐[2H5]phenylpropan‐1‐one, 11, provided the [phenyl‐2H5]‐HEE core structure for synthesis of the desired labeled compound. Copyright © 2005 John Wiley & Sons, Ltd.