Using the semiempirical program PM3 revision of the before proposed scheme of the convertions 4-hydroxymethyl-12-hydroxytetracyclo[7.3.12,7.06,11]tridecane in a hot phosphoric acid was realized. According to new proposed scheme, where disadvantageous stages of Wagner-Meerrwein rearrangements are absent, a final product should be 4-methyl-5-oxotetracyclo [7.3.12,7.06,11]tridecane. We suggested explanation of absence of methyloxadiamantane in reaction products.