Chiastic structure of Ecclesiates

Ecclesiastes, from this source:

Title: author mentioned in third person 1:1

A. the brevity and insignificance of life 1:2-2:26

B. wisdom’s failure to discover life’s meaning 1:12-2:26

C. regarding time 3:1-15

D. fear God 3:16-6:12

C’. time revisited 7:1-14

B’. wisdom’s failure revisited 7:15-10:19

A’. life’s brevity revisited 10:20-12:8

Conclusion: author mentioned in third person 12:9-14

What say you?