Synthetic transformations of higher terpenoids: XXXII. Synthesis of 16-alkenyl-substituted labdatrienes by oxidative coupling of methyl phlomisoate with alkenes
摘要:
Reactions of methyl phlomisoate with methyl acrylate, phenyl acrylate, methyl vinyl ketone, phenyl vinyl ketone, or N-substituted acrylamides catalyzed by Pd(OAc)(2) in the presence of Cu(OAc)(2), p-benzoquinone in the mixture of propionic acid and acetonitrile proceed regio- and stereoselectively with the formation of (E)-16-vinyl labdatrienoates. The oxidative coupling under these conditions of the methyl phlomisoate with styrene results in a mixture of 15,16-distyryl-, 16-styryl-, and 16-(1-phenylvinyl)-derivatives of furanolabdanoid.
Synthetic transformations of higher terpenoids: XXXII. Synthesis of 16-alkenyl-substituted labdatrienes by oxidative coupling of methyl phlomisoate with alkenes
摘要:
Reactions of methyl phlomisoate with methyl acrylate, phenyl acrylate, methyl vinyl ketone, phenyl vinyl ketone, or N-substituted acrylamides catalyzed by Pd(OAc)(2) in the presence of Cu(OAc)(2), p-benzoquinone in the mixture of propionic acid and acetonitrile proceed regio- and stereoselectively with the formation of (E)-16-vinyl labdatrienoates. The oxidative coupling under these conditions of the methyl phlomisoate with styrene results in a mixture of 15,16-distyryl-, 16-styryl-, and 16-(1-phenylvinyl)-derivatives of furanolabdanoid.
Synthetic transformations of higher terpenoids: XXV. Cross coupling of phlomisoic acid methyl ester with alkenes in the presence of oxidants
作者:Yu. V. Kharitonov、E. E. Shul’ts、M. M. Shakirov、G. A. Tolstikov
DOI:10.1134/s107042801104021x
日期:2011.4
The reaction of phlomisoic acid methyl ester with styrene, catalyzed by Pd(OAc)(2), in the presence of Cu(OAc)(2) and 1,4-benzoquinone in a mixture of propionic acid with diethyl ether gave the corresponding 15,16-distyryl derivative and only traces of 15- and 16-monosubstituted furanolabdanoids. Oxidative coupling of the title compound with methyl acrylate under analogous conditions afforded a mixture of 15-mono-, 16-mono-, and 15,16-dialkenylation products whose ratio changed during the process. The reaction was stereoselective, and the exocyclic double bond in the products had exclusively E configuration.