“…Addition of the Grignard or lithio reagent of the THP derivative of 2-methyl-3-butyn-2-ol to a 22-aldehyde moiety 177, then reduction of the triple bond in the resultant propargyl alcohols 178 and 180 to saturated chains 179 and 180, respectively, has been the most popular method for introduction of the ecdysone 182 and crustecydsone 183 side chains (see Table VI). The reaction of acetylenic Grignards proceeds less stereospecifically than alkyl Grignard additions to 22-aldehydes.…”