Chemoenzymatic one-pot reactions with 2c and aromatic aldehydes 1a–1e^a.

Aldehyde	R	4 Yieldb (ratio 1R,3S : 1S,3S)
1a	CH2Ph	4a 40% (1 : 1)
1b	Ph	4b 50% (3 : 1)
1c	4-ClC6H4	4c 25% (3 : 1)
1d	4-BrC6H4	4d 36% (3 : 1)
1e	2-BrC6H4	4e 77% (1 : 1)

^aReaction conditions: (i) 2b/2c and aldehydes (1 : 1.5) (other than 1 h with a ratio of 3 : 1), sodium ascorbate (3 equiv.), CnTYR lysates (10%, v/v) in 0.2 M KPi buffer/CH₃CN (10%, v/v), pH 6.0, 37 °C, 18 h.

^bYields were determined by analytical HPLC (against product standards). Diastereoselectivities were determined by HPLC and ¹H NMR spectroscopy with assignment of the sterochemistry using NOEs (see ESI).³⁰