Hydrolysis of securinine

The effects of micelles of cetyltrimethylammonium bromide (CTABr), tetradecyl-trimethylammonium bromide (TTABr) and sodium dodecyl sulfate (SDS) on the rates of alkaline hydrolysis of securinine (223) were studied at a constant [HO ] (0.05 m). An increase in the total concentrations of CTABr, TTABr and SDS from 0.0 to 0.2 M causes a decrease in the observed pseudo-first-order rate constants (kobs) by factors of ca 2.5, 3, and 7, respectively. The observed data are explained in terms of pseudophase and pseudophase ion-exchange (PIE) models of micelles. Cationic micelles of CTABr speed attack of hydroxide ion upon coumarin (224) twofold owing to a concentration effect. ... 

Lajis, N.H., Khan, M.N. Effects of ionic and non-ionic micelles on rate of hydroxide ion-catalyzed hydrolysis of securinine. J. Phys. Org. Chem. 1998, 11(3), 209-215. 

With compound 190 in hand in reasonable amount the stage was set for attempting to effect the construction of ring B of securinine. Deacetylation of 190 followed by formylation and allylic bromination gave the A-formyl bromide 194 in moderate overall yield. Compound 194 upon acid hydrolysis followed by base treatment gave d -securinine... 

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