(2S)-ethylmalonyl-CoA + NADP(+) = (2E)-butenoyl-CoA + CO2 + NADPH
(2s)-ethylmalonyl-coa + nadp(+) = (2e)-butenoyl-coa + co2 + nadph
"crotonyl-CoA reductase (carboxylating)"
"crotonyl-coa reductase (carboxylating)"