Unknown 'a' CIP stereochemistry cause error in CDXML parser

[Zhirnoff]

Description:
When copying a structure from ChemDraw (version 23.1.2) and pasting it into Ketcher, a reaction arrow is pasted instead of the intended structure. This issue is specific to certain example structures and was not reproducible in older versions of ChemDraw. Similar-sized molecules do not exhibit this behavior, indicating that it may be specific to certain structural characteristics.

Steps to Reproduce:

1. Open ChemDraw (version 23.1.2) and load structure files.zip
2. Copy the structure using Ctrl + C.
3. Open Ketcher and paste the copied structure.

Note: If we paste the structure, for example, into Word, it pastes correctly.

Actual behavior
Instead of the structure, a reaction arrow is pasted into Ketcher, sometimes nothing is pasted at all. The issue seems to occur only with specific example structures provided by the user.

Expected behavior
The structure from ChemDraw should paste correctly into Ketcher without any alterations.
This is how the structure should look in Ketcher:

This is how the structure looks in ChemDraw:

Desktop:

• OS: Windows 11
• Browser Chrome
• Version 128.0.6613.120 (Official Build) (64-bit)

Ketcher version
[Version 2.26.0-rc.6]
Indigo version
[Version 1.25.0-rc.4]

#188509377

[AliaksandrDziarkach]

Error caused by unknown 'a' CIP stereochemistry option.
In cdxml it saved as 'AS="a"'.
Need to fix parser to avoid errors on unknown CIP stereo options.
Also latest Chemdraw shoud be checked to find what this option means.

[AlexeyGirin]

Verified.

• Ketcher Version 2.26.0-rc.9 Build at 2024-11-11; 12:01:35
• Indigo Toolkit Version 1.25.0-rc.5.0-g45d28b8ca-wasm32-wasm-clang-19.0.0
• Chrome Version 130.0.6723.117 (Official Build) (64-bit)
• Win10