A newly synthesized SCR gene was expressed in E. coli for (S)-ET-5 production. The bioproduction of (S)-ET-5 in a biphasic solvent was first constructed. The (S)-ET-5 was achieved by bioconversion without extra addition of cofactor. The conversion of 99.1%, d.e. > 99.9% was achieved at 150 g L−1 ET-4.