Concise and Practical Total Synthesis of (+)-Abscisic Acid

(+)-Abscisic acid 1 was obtained in a concise total synthesis from ethyl 2,6,6-trimethyl-4-oxocyclohex-2-ene-1-carboxylate ( 2 ) with 41% overall yield in seven steps. A hydroxyl group was stereoselectively introduced by Sharpless asymmetric epoxidation; then, the side chain was appended with dimethyl 2-(propan-2-ylidene)malonate ( 7 ); subsequently, selective decarboxylation of diacid 8 established the Z -configuration of the conjugated acid 1 .