Organic Structure Challenge Recently we had this challenge in our Organic Chemistry Department.
I was not involved in it but I thought it might be interesting for the SE Chemistry site, so here it is.

Propose a structure for C20H18 with the longest IUPAC name.
Following rules apply:


Names must be generated with MarvinSketch: Structure>Generate Name…>Preferred IUPAC Name (https://www.chemaxon.com/products/marvin).
No isotopic markings can be used.
The structures must be possible (no cycles with too much unsaturations nor systems with impossible tension).
All the characters will be counted: numbers, letters, points, colons, dashes, everything.
Longest name wins.


Here is the example that was given:



and the name provided by MarvinSketch:

(1'R,4'Z,6'Z,8'Z,10'Z,12'S,15'R,16'R,17'R)-spiro[cyclopropane-1,18'-tetracyclo[13.2.1.04,17.012,16]octadecane]-2,2',4',6',8',10',13'-heptaene

141 characters

Good luck and prosperous year 2018!

EDIT

Well, what is a challenge without a prize?
So, I have set a bounty worth +50 reputation for the longest name.
Sorry, I can not spend much more on it.
Remember that you can post more than one structure.
If you have proposed one and after some days you find a structure with a longer name, you can post it too.
$\ce{C20H18}$, 246 characters


InChI=1S/C20H18/c1-2-13(1)5-15(13)7-17(15)9-19(17)11-12(19)20(11)10-18(20)8-16(18)6-14(16)3-4-14/h1-4,11-12H,5-10H2/t11-,12+,15-,16-,17-,18-,19-,20-/m1/s1
PIN: (1'R,1''R,1'''R,1''''R,1'''''R,1''''''R,2''''R,3''''S)-octaspiro[tetrakis(cyclopropane)-1,2':1',2'':1'',2''':1''',4''''-bicyclo[1.1.0]butane-2'''',2''''':1''''',2'''''':1'''''',2''''''':1''''''',1''''''''-tetrakis(cyclopropane)]-2,2''''''''-diene