Callitrisic acid

An alternative synthesis of the tricyclic intermediate (168), together with the elaboration of C-4 with the configuration of both podocarpic and dehydroabietic acids, has been reported. In a stereoselective total synthesis of ( )-callitrisic acid and ( )-podocarpic acid, the C-4 stereochemistry was established by reductive methylation of the enol-ether (169). 

The Chemistry of Ring A.—Two methods have been described for smoothly hydrolysing the highly-hindered axial C-4 methyl esters such as methyl 0-methyl podocarpate. The first uses boron trichloride in methylene chloride, and the otherlithium n-propyl mercaptide in hexamethylphosphoramide. The oxidative decarboxylation of dehydroabietic acid and 0-methyl podocarpic acid affords a mixture of C-4 olefins which are separable over 10 % silver nitrate by t.l.c. Thus in a partial synthesis of callitrisic acid, the 4(19)-epoxide prepared... 

Callitrisic acid (4-epidehydroabietic acid) has been synthesized from podo-carpic acid. After insertion of the isopropyl group, the phenolic hydroxy-group... 

Calacone, T16 Calamenene, T16 Calarane, T26 Calciferol, T48 Calcorene, T16 Caldariomycin, Y16 Callicarpone, T33 Callitrisic acid, T33 Calodendrolide, T16 Calycanthidine, K26 Calycanthine, K26 Calycotomine, K2 Camphene, Til Camphenilone, Til Campherenone, T28 Campholic acid, A36 Camphonanic acid, T12 Camphor, Til cw-camphoric acid, T12 Camphoronic acid, T12 Camphorquinone, T12 Camphorsulphonic acids, T11-12 Camptothecin, K29 Canallinin, Z8 Canaric acid, T43 Cancentrine, K2 ... 

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