Sensitivity of substitution to the extent of self-immolative dhirality transfer during reaction cascades originating form squarate esters

摘要

Reaction cascades induced by the addition to diisopropyl squarate of at least one cycloalkenyl anion possessing an oxygenated leaving group have been examined for the purpose of evaluating the level of chirality transferred to several new stereogenic centers as the original one is destroyed through β-elimination. A methoxy group alone necessarily resides too far from the bonding sites involved in conrotatory ring closure of the coiled octatetraene intermediate to have a large impact, viz.