Reduction of ethyl 3-methyl-, 3-isopropyl-and 3-n-pentyl-3-[dimethyl (phenyl) silyl] propanoates 4 with DIBAL to the aldehydes 5, enol trifluoromethanesulfonate (triflate) formation using trifluoromethanesulfonic (triflic) anhydride and 2, 6-di-tert-butylpyridine, and elimination using LDA, gives the propargyl silanes 8. The esters 4 could also be prepared enantiomerically enriched (11), and the final products are the enantiomerically enriched ...
