OrgoMech is an iOS app for organic chemistry students and pre-meds. You draw or pick a reactant, add reagents, predict the major product, then practice ordering the curved-arrow mechanism steps — the same skills tested on exams and the MCAT.

Is OrgoMech good for MCAT organic chemistry?

Yes. OrgoMech focuses on reaction outcomes, stereochemistry, and mechanism arrow-pushing — core skills for the organic chemistry section of the MCAT and undergraduate orgo courses.

How is OrgoMech different from memorizing reactions?

Instead of isolated facts, you see why a product wins (regiochemistry and stereochemistry) and practice electron-pushing in sequence. The reaction library groups mechanisms by type with the trap answers students confuse on tests.

Does OrgoMech include a reaction mechanism practice mode?

Yes. After predicting the product, you order the mechanism steps — nucleophile attack, leaving group departure, and pi bond formation — matching graded mechanism questions.

Where can I download OrgoMech?

OrgoMech is available on the Apple App Store for iPhone and iPad in the United States and other regions where the app is listed. Use the Download on the App Store link on this site.

What is an organic chemistry reaction predictor?

It is software that takes a starting structure and reagents, then outputs the likely major product and often the mechanism. OrgoMech Predict does this on iOS with drawable structures, 50+ reagent chips, and step-by-step curved arrows.

Can I draw my own molecule instead of picking a template?

Yes. Use Structure mode to place atoms and bonds, or tap a quick-start shape and edit it. Templates cover common exam starting materials such as 1-bromobutane, cyclohexene, and benzaldehyde.

How does OrgoMech predict the major product?

It matches your reactant and reagents to reactions in its library, applies the mechanism to your structure when possible, and ranks major vs minor products using the same regiochemistry and stereochemistry rules taught in undergraduate orgo.

What if SN1 and SN2 both seem possible?

Predict shows when multiple mechanisms fit and lets you switch pathways. For a deeper decision tree, read the free SN1 vs SN2 mechanism hub on this site, then test cases in the app.

Does the predictor show electron-pushing arrows?

Yes. After the product summary, a step-by-step mechanism viewer shows curved arrows, plain-language step titles, and navigation between steps — the same flow as the reaction library.

Is the reaction predictor free on the web?

This page explains how Predict works. Running predictions, full mechanisms, and the 56-reaction library require OrgoMech Pro on iPhone or iPad via the App Store.

Who is the reaction predictor for?

Undergraduate organic chemistry students, pre-meds preparing for the MCAT, and anyone who needs to practice predicting products and ordering mechanism steps before midterms or finals. Content is framed for U.S. courses (en-US).

How is this different from reading a textbook?

Textbooks explain general rules; Predict applies them to the exact molecule you draw and the reagents you select, including trap answers like Hofmann vs Zaitsev or Markovnikov vs anti-Markovnikov when those pathways compete.

Can Predict help with multi-step synthesis?

Yes — run one step at a time on each intermediate to verify the major product before writing a full route on an exam. See the multi-step synthesis hub for retrosynthesis order and protecting groups.

Organic Chemistry Reaction Predictor — Draw, Add Reagents & Predict Products

How the reaction predictor works (3 steps)

The Predict tab in OrgoMech follows the same flow as a exam problem: reactant → reagents → products & mechanism.

Reactant — draw or choose a template
Sketch your starting material in Structure mode or load one of 29 catalog templates (alkyl halides, alkenes, carbonyls, aromatics, and more).
Step 1 · Reactant
2-Bromobutane · Alkyl halide · C₄H₉Br
- Structure tools: place atoms (C, O, N, halogens), single/double/triple bonds, move, erase, undo, and 14 quick-start shapes such as 1°/2°/3° alkyl bromide, alkene, aldehyde, ketone, ester, and benzene.
- Live feedback shows molecular formula, recognized functional groups, valence warnings, and matches to named catalog molecules when your drawing is complete.
- Freehand mode is for notes only — predictions run from Structure mode or templates.
Reagents — 50+ conditions in one tap
Filter by category (base, nucleophile, acid, Grignard, oxidation, reduction, hydroboration, Friedel–Crafts, and more) and combine reagents the way exam problems list them.
Step 2 · Reagents
NaOH (aq) · Nucleophile / base
- Examples: NaOH, t-BuOK, HBr, HBr + ROOR, Br₂, NBS, NaBH₄, LiAlH₄, PCC, KMnO₄, BH₃·THF, CH₃MgBr, AlCl₃, heat (Δ), and hv.
- Selected reagents appear in a row — remove any with × before you predict again.
Results — major & minor products, then mechanisms
Tap Predict products to see the matched reaction name, confidence score, major and minor products with yields, and why that regiochemistry and stereochemistry win.
Step 3 · Results
SN2 · Major: 2-Butanol · Walden inversion
- Step through curved-arrow mechanisms with Prev/Next and labeled steps (for example nucleophilic approach, leaving group departure).
- Finishing the last mechanism step marks the reaction studied toward your library progress.
- If no pathway fits, OrgoMech suggests reagents to try next.

What you see after you predict

Major vs minor product
Each product is labeled MAJOR or MINOR with a typical yield bar and a short explanation — the same distinction homework and exams grade.
Regiochemistry & stereochemistry
See why the nucleophile attacks here, why anti addition applies, or why SN2 inverts configuration — not just the final line structure.
Multiple mechanisms fit
When your reactant and reagents could follow more than one pathway, OrgoMech lists candidate reactions with scores so you can compare SN1 vs SN2, E1 vs E2, or radical vs ionic addition.
Confidence score
A green, amber, or red match percentage shows how closely your drawing and reagents align with a catalog reaction — useful when conditions are ambiguous.

When mechanisms compete — study the hubs, test in Predict

Search traffic and exam questions cluster on a few decision points. Read the free guides, then swap reagents in the app to see the major product change.

SN1 mechanism vs SN2 — substrate, solvent, and stereochemistry (inversion vs racemization).
Grignard mechanism & carbonyl addition — RMgBr with aldehydes, ketones, and esters; dry conditions.
E1 vs E2 elimination — bulky base Hofmann vs Zaitsev regiochemistry.
Alkene addition — Markovnikov, anti addition, hydroboration syn stereochemistry.
Stereochemistry (R/S, meso) — read wedges and dashes on the product Predict draws.

Draw it. Add reagents. Predict the product.

Download OrgoMech on iPhone or iPad for the full reaction predictor, 56-reaction library, and daily exam drill.

Download on theApp Store

Reaction predictor FAQ

Common questions about organic chemistry product prediction and OrgoMech Predict.

What is an organic chemistry reaction predictor?: It is software that takes a starting structure and reagents, then outputs the likely major product and often the mechanism. OrgoMech Predict does this on iOS with drawable structures, 50+ reagent chips, and step-by-step curved arrows.
Can I draw my own molecule instead of picking a template?: Yes. Use Structure mode to place atoms and bonds, or tap a quick-start shape and edit it. Templates cover common exam starting materials such as 1-bromobutane, cyclohexene, and benzaldehyde.
How does OrgoMech predict the major product?: It matches your reactant and reagents to reactions in its library, applies the mechanism to your structure when possible, and ranks major vs minor products using the same regiochemistry and stereochemistry rules taught in undergraduate orgo.
What if SN1 and SN2 both seem possible?: Predict shows when multiple mechanisms fit and lets you switch pathways. For a deeper decision tree, read the free SN1 vs SN2 mechanism hub on this site, then test cases in the app.
Does the predictor show electron-pushing arrows?: Yes. After the product summary, a step-by-step mechanism viewer shows curved arrows, plain-language step titles, and navigation between steps — the same flow as the reaction library.
Is the reaction predictor free on the web?: This page explains how Predict works. Running predictions, full mechanisms, and the 56-reaction library require OrgoMech Pro on iPhone or iPad via the App Store.
Who is the reaction predictor for?: Undergraduate organic chemistry students, pre-meds preparing for the MCAT, and anyone who needs to practice predicting products and ordering mechanism steps before midterms or finals. Content is framed for U.S. courses (en-US).
How is this different from reading a textbook?: Textbooks explain general rules; Predict applies them to the exact molecule you draw and the reagents you select, including trap answers like Hofmann vs Zaitsev or Markovnikov vs anti-Markovnikov when those pathways compete.
Can Predict help with multi-step synthesis?: Yes — run one step at a time on each intermediate to verify the major product before writing a full route on an exam. See the multi-step synthesis hub for retrosynthesis order and protecting groups.

Undergraduate orgo references (external)

Open textbooks and reference sites for the same topics covered above. We link out to established science education publishers — not affiliate pages.

Organic Chemistry (OpenStax) — OpenStax
Organic Chemistry LibreTexts — LibreTexts
MIT OpenCourseWare — Organic Chemistry I — MIT OCW
PubChem — NIH NLM

Organic chemistry reaction predictor: draw your reactant, add reagents, predict the major product

How the reaction predictor works (3 steps)

Reactant — draw or choose a template

Reagents — 50+ conditions in one tap

Results — major & minor products, then mechanisms

What you see after you predict

Major vs minor product

Regiochemistry & stereochemistry

Multiple mechanisms fit

Confidence score

When mechanisms compete — study the hubs, test in Predict

Draw it. Add reagents. Predict the product.

Reaction predictor FAQ

More on OrgoMech.com

Undergraduate orgo references (external)