Methoxy vincamine

The knowledge of the key fragmentation routes of eburnamine and some related alkaloids confirmed or elucidated the structures of the alkaloids 11-methoxy-vincamine,100 vincaminine,102 and vinci-nine,102 of the same skeletal type as eburnamine. Alkaloids of the mavacurine-pleiocarpamine group (212)103 are characterized by a key fragment corresponding to the loss of the ester group and... 

C17H21CIN2O4 59639-73-5) see Vincamine (135-cis)-13-ethyl-7,ll,12,13,16,17-hexahydro-3-methoxy-6//-cycIopenta[a]phenanthren-17-oI acetate ( 22112 03 2911-81-1) see Levonorgestrel 3-ethylhexahydro-3-(3-methoxyphenyl)-lH-azepine (C15H23NO 27180-90-1) see Meptazinol... 

In the laboratory of A.G. Schultz during the asymmetric total synthesis of two vincane type alkaloids, (+)-apovincamine and (+)-vincamine, it was necessary to construct a crucial c/s-fused pentacyclic diene intermediate. The synthesis began by the Birch reduction-alkylation of a chiral benzamide to give 6-ethyl-1-methoxy-4-methyl-1,4-cyclohexadiene in a >100 1 diastereomeric purity. This cyclohexadiene was first converted to an enantiopure butyrolactone which after several steps was converted to (+)-apovincamine. 

Seven alkaloids have been isolated/ including tabersonine, voaphylline, A " -vincamine, 16-epi-A -vincamine, 12-methoxy-A -vincamine, and A -apovincamine, which have previously been isolated from the root bark. The seventh alkaloid criocerine, is new, and has been assigned the structure and absolute configuration (159), on the basis of its spectroscopic properties and its partial synthesis by a Polonovski reaction on the N-oxide of A -vincamine. ... 

From the physical and analytical data 16-epivincamine could have differed from vincamine in the position of the hydroxyl and/or methoxy-carbonyl or was simply a stereoisomer. That the latter was true followed from its reduction to a diol with lithium aluminum hydride oxidation of which furnished 1-eburnaminone. Heating 16-epivincamine in dry... 

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