Michael addition
specified-next: primitive moves are explicit; executable guarded v2 rules are pending.
Interactive Route Player
Use next/prev to step through the route: first the current state is shown without highlight, then the next ownership move is previewed, then the move is executed. If a route snapshot changes several ownership records, the player unfolds them one at a time. Drag a node to fix it; double-click a fixed node to release it.
HEG v2 State Sketches
These panels are rendered from ownership-structured HEG v2 objects. For specified-next examples they are state sketches, not yet products of executable v2 rules.
Michael substrate HEG sketch
Hydroxide-like nucleophile plus alpha,beta-unsaturated aldehyde.
Michael 1,4 route step 1
Primitive snapshot: nucleophile lone pair has become a Nu-C_beta shared pair.
Michael 1,4 route step 2
Primitive snapshot: alkene pi resource has shifted toward the carbonyl carbon.
Michael 1,4 route enolate
Conjugate-addition enolate: carbonyl oxygen carries the anionic lone-pair resource.
Michael 1,2 route step 1
Competing primitive snapshot: nucleophile attacks the carbonyl carbon instead of C_beta.
Michael 1,2 route alkoxide
Competing carbonyl-addition state after carbonyl pi resource moves to oxygen.
DPO-like Step Panels
Each primitive snapshot is shown as L/K/R. Red marks the ownership edge removed from L, orange marks the halfedge whose owner changes, and green marks the ownership edge created in R. K keeps the common atoms, halfedges, pair objects, and unchanged ownership records. For specified-next examples this is an explanatory span derived from route snapshots, not yet a checked executable rule application.
Michael 1,4 route step 1
Michael substrate HEG sketch -> Michael 1,4 route step 1
h4: a1 -> a3
L
K
R
Michael 1,4 route step 2
Michael 1,4 route step 1 -> Michael 1,4 route step 2
h9: a3 -> a8
L
K
R
Michael 1,4 route step 3
Michael 1,4 route step 2 -> Michael 1,4 route enolate
h21: a8 -> a9
L
K
R
Michael 1,2 competitor route step 1
Michael substrate HEG sketch -> Michael 1,2 route step 1
h4: a1 -> a8
L
K
R
Michael 1,2 competitor route step 2
Michael 1,2 route step 1 -> Michael 1,2 route alkoxide
h21: a8 -> a9
L
K
R
Reaction Sketch
Specified as a guarded primitive HEG mechanism. It is especially useful because it has a real alternative: direct 1,2-carbonyl addition.
Mechanism Flow
Alternative Route Probe
Primitive Steps
nucleophile lone pair forms bond to beta carbon
lone pair to shared pair: LP(Nu) -> sigma(Nu,C_beta)
requires conjugated C_alpha=C_beta-C=O acceptor and no existing Nu-C_beta bond
alkene pi pair shifts toward alpha carbon
shared pair endpoint transfer: pi(C_alpha,C_beta) -> pi(C_carbonyl,C_alpha) or enolate C_alpha resource
requires conjugated pi system and correct atom ordering
carbonyl pi pair becomes oxygen lone pair
shared pair to lone pair: pi(C_carbonyl,O) -> LP(O)
requires carbonyl pi resource
enolate is protonated
lone pair to shared pair: LP(enolate atom) -> sigma(enolate atom,H)
requires proton donor and admissible product
Guards and Alternatives
Guards
- acceptor must be alpha,beta-unsaturated carbonyl, not an isolated alkene.
- nucleophile must be compatible with conjugate attack.
- 1,2-carbonyl addition should be a separate competing guarded rule, not an accidental match of this rule.
Route probes
- 1,4-Michael addition vs 1,2-carbonyl addition is a genuine alternative route search target.
- Hard/soft nucleophile policy can be encoded as rule availability weights or guards later.