Structural investigation of lac resin. Part 14. Model esters related to lac resin
Model esters formed from the 12- and 15-carboxy-functions of shellolic acid and its 2-epimer with the C-16-position of methyl threo-aleuritate are reported. While stearate esters involving the hydroxy-groups of the above two terpenes were readily obtained through the acid chloride or the mixed anhydride procedure, the corresponding mixed threo-aleuritic–carbonic anhydride failed to react. The results indicated the greater stability and preferential ester formation with mixed stearic–carbonic anhydride at C-13 rather than at C-10.