Benzene → Ethyl 3-(4-cyclopentylphenyl)but-2-enoate

Reaction equation

[Na+:42].[O-:38][C:39]([OH:40])=[O:41].[OH:1][C:2]([CH2:3][C:4](=[O:5])[O:6][CH2:7][CH3:8])([CH3:9])[c:10]1[cH:11][cH:12][c:13]([CH:16]2[CH2:17][CH2:18][CH2:19][CH2:20]2)[cH:14][cH:15]1.[c:21]1([CH3:22])[cH:23][cH:24][c:25]([S:26]([OH:27])(=[O:28])=[O:29])[cH:30][cH:31]1.[cH:32]1[cH:33][cH:34][cH:35][cH:36][cH:37]1>>[C:2](=[CH:3][C:4](=[O:5])[O:6][CH2:7][CH3:8])([CH3:9])[c:10]1[cH:11][cH:12][c:13]([CH:16]2[CH2:17][CH2:18][CH2:19][CH2:20]2)[cH:14][cH:15]1