2-(2-methyl-allyloxy)-pent-4-enoic acid ethyl ester 在
tricyclohexylphosphine (1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazol-2-ylidene) (benzylidene)ruthenium (IV) dichloride 作用下,
以
二氯甲烷 为溶剂,
反应 0.83h,
以92%的产率得到5-methyl-3,6-dihydro-2H-pyran-2-carboxylic acid ethyl ester