ORGANIC CHEMISTRY · MULTISTEP SYNTHESIS MAP
Turn targets into functional-group and scaffold requirements, connect explicit intermediate states, account for competing reactive sites, and reject any route whose compatibility, workup, or atom ledger fails.
THE ROUTE AUDIT
Translate the target into atom, bond, functional-group, regioselective, and stereochemical changes.
Work backward only through transformations whose forward use and limits are known.
Reverse the plan and verify every intermediate, condition, preserved group, and workup in order.
Reject broken atom ledgers, incompatible conditions, incomplete protection cycles, and attractive but infeasible shortcuts.
FOUR OFFICIAL SYNTHESIS LINES
Each bank contains one source-linked lesson and four independently keyed cases. The four-case instructional pattern is a DAT TRAIN retrieval design, not an ADA topic weight.
OC-SYN-TWO-01 · OC-SYN-TWO-02 · OC-SYN-TWO-03
Work backward to a nitrile precursor, then run cyanide substitution and nitrile hydrolysis; the cyanide carbon supplies the one-carbon increase.
Reduce the ketone to cyclohexanol first, then dehydrate the alcohol; reversing the order offers no leaving group for the elimination step.
Peroxide-promoted HBr addition creates the primary bromide, and SN2 cyanide substitution then installs the fourth carbon and nitrile group.
LiAlH4 reduction gives two ethanol molecules, and dehydration converts both alcohol products to ethene while the four-carbon total remains balanced.
OC-SYN-MUL-01 · OC-SYN-MUL-02 · OC-SYN-MUL-03
Disconnect the methyl–alkyne bond to a terminal acetylide and reserve Lindlar reduction for the final stereochemistry-setting operation.
Alkylate acetylide first, partially reduce the terminal alkyne to the alkene, then use hydroboration–oxidation to place the alcohol at the terminal carbon.
Install the acyl group first to direct chlorination meta, then reduce that carbonyl to the propyl group after its directing job is complete.
Reject the incompatible shortcut, then choose the selective four-operation route: its 81.45% yield exceeds the eligible three-step route's 57.38%.
OC-SYN-MFG-01 · OC-SYN-MFG-02 · OC-SYN-MFG-03
The free alcohol would quench organomagnesium chemistry, so protect it, form the Grignard reagent, carboxylate, and remove the protecting group before declaring the target reached.
Use NaBH4 to reduce the aldehyde while preserving the ester, then hydrolyze the ester to the carboxylic acid.
Acylate first and nitrate second; nitration first would strongly deactivate the ring and block the later Friedel–Crafts step.
Controlled oxidation creates the aldehyde while preserving the alkene; methyl Grignard addition then changes only the aldehyde-derived center and explicitly preserves the alkene again.
OC-SYN-GEN-01 · OC-SYN-GEN-02 · OC-SYN-GEN-03
The target needs one new carbon, leaving-group replacement, and nitrile-to-acid conversion; cyanide substitution followed by hydrolysis satisfies all three requirements.
Use the ketone-to-alcohol reduction function, then the alcohol-to-alkene dehydration function; each function includes the boundary that its required input group must exist.
Compatibility and selectivity are hard gates; only after excluding the shortcut should overall yield choose the longer 81.45% route over the 57.38% route.
The route is feasible only with a dry protected Grignard stage, delayed aqueous workup, one-carbon dioxide capture, and deprotection before the final hydroxy-acid state.
SOURCES AND LIMITS
The four topic lines come from the ADA Organic Chemistry specification ↗. Free OpenStax chapters support the reaction and planning boundaries; the route cases and questions are original DAT TRAIN work.
This route completes first-pass coverage of all sixty-three frozen Organic Chemistry objectives. The separate completion form provides full-section delivery. Official-score prediction is not offered, and expert review, device testing, and pilot calibration remain open.