When a 10-Carbon Unit and a 5-Carbon Unit Condense to a 15-Carbon

Essay

When a 10-carbon unit and a 5-carbon unit condense to a 15-carbon intermediate in the pathway to cholesterol, the mechanism of condensation is basically different from that of the condensation of two 15-carbon units to the 30-carbon compound squalene. Describe the two condensations in enough chemical detail to illustrate the difference between them. (You should show relevant structures.)