There are several synonyms for the phrase "when opportune." These include "when the time is right," "when the moment presents itself," "when circumstances align," "when conditions are favorable," "when the stars align," and "at the appropriate time." These synonyms convey the idea of waiting for the perfect moment to act or make a decision. It is important to be patient and discerning, observing the situation carefully in order to determine when the opportune time has arrived. By using these synonymous phrases, one can communicate effectively the importance of timing and careful consideration in decision-making.