Me(2)CHCHO was trimerized to Me(2)CHCH(OH)CMe(2)CH(2)OCOCHMe(2) and Me(2)CHCOOCH(i-Pr)CMe(2)CH(2)OH esters at 60 degrees C in presence of NaOH for 2-60 min to det. the kinetic curves and study the reaction mechanism. The mat model of the reaction was exp. verified.