Treatment of meso-diols 3 and 6 with CCL and vinyl acetate without solvent produced the AE part of Aconitium alkaloids 2 and 7 in 68% and 75% yields, respectively, with > 96% e.e. Quantitative formations of their MTPA esters 4 and 8 were achieved by reaction with MTPA in the presence of DCC and DMAP in ClCH2CH2Cl.
Stereoselective total synthesis of (.+-.)-atisine via intramolecular double Michael reaction