In enzymology, a 5-O-(4-coumaroyl)-D-quinate 3'-monooxygenase (EC 1.14.13.36) is an enzyme that catalyzes the chemical reactiontrans-5-O-(4-coumaroyl)-D-quinate + NADPH + H+ + O2 trans-5-O-caffeoyl-D-quinate + NADP+ + H2O