Example Project: Design

Summary: Find all "reasonable" C_xH_yO_z compounds.

Library design criteria:

All carbon + oxygen compounds for C1-C6.
No 3- or 4-member rings (via SMARTS).
Maximum one hetero ring atom (via SMARTS).
ClogP requirement: valid ClogP exists
Energy requirement (not implemented).
C:O ratio > 1.0 (quasi-energy requirement).

Initial (seed) SMILES:

C, CC, CCC, CCCC, CCCCC, CCCCCC (methane ... hexane)

Reaction Transforms -- SMIRKS file "grow.smk":

[C;H1,H2;!R:1]([H])[!R:2][!R:3]>>[C:1]([*:3])[*:2][H]
[C&!$(C(O)O):1]([H])>>[C:1]O

[C;H3,H4:1]([H])([H])[H]>>[C:1](=O)O
[C:1][C:2]>>[C:1]O[C:2]

[C;H2,H3,H4:1]([H])[H]>>[C:1]=O
[H][C:1]-[C:2][H]>>[C:1]=[C:2]

[H][C:1]=[C:2][H]>>[C:1]#[C:2]
[H][C!R:1][!R:2][!R:3][C!R:4][H]>>
[*:1]1[*:2][*:3][*:4]1

[H][C!R:1][!R:2][!R:3][!R:4][C!R:5][H]>>
[*:1]1[*:2][*:3][*:4][*:5]1
[H][C!R:1][!R:2][!R:3][!R:4][!R:5][C!R:6][H]>>
[*:1]1[*:2][*:3][*:4][*:5][*:6]1

Reject-SMARTS list:

*~1~*~*~1 3-member ring

*~1~*~*~*~1 4-member ring

[!#6R].[!#6R] 2 hetero ring-atoms

EuroMUG'99 -- 28-29 October 1999 -- Cambridge, UK

Daylight Chemical Information Systems Inc.
info@daylight.com

*[C;H1,H2;!R:1]([H])[!R:2][!R:3]>>[C:1]([:3])[:2][H]*	[C&!$(C(O)O):1]([H])>>[C:1]O
[C;H3,H4:1]([H])([H])[H]>>[C:1](=O)O	[C:1][C:2]>>[C:1]O[C:2]
[C;H2,H3,H4:1]([H])[H]>>[C:1]=O	[H][C:1]-[C:2][H]>>[C:1]=[C:2]
[H][C:1]=[C:2][H]>>[C:1]#[C:2]	[H][C!R:1][!R:2][!R:3][C!R:4][H]>> [:1]1[:2][:3][:4]1
[H][C!R:1][!R:2][!R:3][!R:4][C!R:5][H]>> [:1]1[:2][:3][:4][*:5]1	[H][C!R:1][!R:2][!R:3][!R:4][!R:5][C!R:6][H]>> [:1]1[:2][:3][:4][:5][:6]1

~1~~*~1	3-member ring
~1~~~~1	4-member ring
[!#6R].[!#6R]	2 hetero ring-atoms