--- title: "Condensed Formula to Structure Converter | MolDraw" url: https://www.moldraw.com/tools/free-chem-tools/condensed-formula-to-structure.html description: "Free condensed formula to structure converter: type CH3CH2OH or (CH3)2CHCOOH and get the skeletal drawing, SMILES, formula, molar mass and IUPAC name." lang: en publisher: Scidart Academy generated: 2026-10-31 --- [MolDraw](https://www.moldraw.com/) › [Chemistry tools](https://www.moldraw.com/tools/) › Condensed Formula to Structure Converter # Condensed Formula to Structure Converter **In short:** Type a condensed formula as you would write it in class, such as `CH3CH2OH` or `(CH3)2CHCOOH`. You get the skeletal structure, the SMILES, the molecular formula, the molar mass and the IUPAC name. If the formula fits more than one molecule, all of them are shown. **Quick answer:** `CH3COOCH2CH3` is ethyl acetate, SMILES `CCOC(C)=O`, C4H8O2, 88.106 g/mol. `(CH3)2CHCOOH` is 2-methylpropanoic acid, `CC(C)C(=O)O`. Condensed formula Use capital letters for elements. Bonds: - = ≡ (or #). Groups such as Ph, Me, Et, iPr, tBu, Ac, OMe, NO2, CN, COOH, CHO and CONH2 are understood. Examples: Loading… ## How to use the condensed formula converter 1. Type a condensed formula, for example `CH3CH(NH2)COOH`, or press one of the examples. 2. Press **Draw structure** (or Enter). The line **Read as** shows how the formula was split into groups. 3. Check the skeletal drawing, SMILES, molecular formula, molar mass and IUPAC name. If the formula is ambiguous, every possible molecule is shown; click the one you mean. 4. Press **Copy SMILES**, **Download .mol** or **Download .svg**, or open the structure in the MolDraw editor. ## What a condensed formula is A **condensed formula** (or semi-structural formula) writes a molecule as a row of groups instead of drawing every bond. Each carbon is followed by its hydrogens and by the atoms bonded to it, and the groups are read left to right. `CH3CH2OH` means CH3–CH2–OH, ethanol. A **molecular formula** such as C2H6O only counts atoms and cannot be drawn without guessing. ### How the tool reads a formula | Rule | Example | Read as | | --- | --- | --- | | H atoms belong to the atom just before them | `CH3CH2OH` | CH3–CH2–O–H | | Each new carbon bonds to an earlier atom that still has a free valence | `CH3OCH3` | CH3–O–CH3 | | Double and triple bonds come from valences (C 4, N 3, O 2, halogens 1) | `CH3CHO`, `CH3CCH` | CH3–CH=O, CH3–C≡CH | | CO, COO, CONH2 after a carbon are carbonyl groups | `CH3COOCH2CH3` | CH3–C(=O)–O–CH2CH3 | | (group)n at the start: n groups on the next atom | `(CH3)3COH` | three CH3 on C, then OH | | (group) after an atom: a branch on that atom | `CH3CH(NH2)COOH` | NH2 on the second carbon | | (unit)n with two free bonds: a chain | `CH3(CH2)4CH3` | hexane | | Groups written backwards at the start | `HOOC-CH2-COOH`, `Cl2C=CCl2` | malonic acid, tetrachloroethene | | A charge at the end, or a metal salt | `CH3COO-`, `CH3COONa` | acetate; sodium acetate as Na+ and acetate | ### Abbreviations `Ph` and `C6H5` phenyl, `C6H4` benzene ring with two groups (add `o-`, `m-` or `p-`), `C6H11` cyclohexyl, `Me` methyl, `Et` and `C2H5` ethyl, `Pr` propyl, `iPr` isopropyl, `Bu` butyl, `tBu` tert-butyl, `Ac` acetyl, `Bz` benzoyl, `Bn` benzyl, `OMe`, `OEt`, `OAc`, `NHAc`, `NO2` nitro, `SO3H`, and the groups `OH`, `NH2`, `CN`, `CHO`, `COOH`, `COCl`, `CONH2` written atom by atom. `C3H7` and `C4H9` are flagged as ambiguous because they can be several different groups. ### When a formula is ambiguous The tool tries every way of joining the groups that keeps normal valences. If two different molecules fit, it says so and shows both. It never picks one silently. Readings that only work with an O–O bond (a peroxide) are ignored when a normal reading exists, and the page says how many were ignored. ## Worked examples ### CH3COOCH2CH3 The C after CH3 carries both O atoms: one C=O and one O that links to CH2CH3. Ethyl acetate, CCOC(C)=O, C4H8O2, 88.106 g/mol ### (CH3)2CHCOOH Two CH3 groups sit on the CH, which carries the COOH group. 2-Methylpropanoic acid, CC(C)C(=O)O, C4H8O2 ### CH3(CH2)4CH3 (CH2)4 is four CH2 units in a row. Hexane, CCCCCC, C6H14, 86.178 g/mol ### CH3C≡CH The middle carbon has only two neighbours, so the bond to CH is triple. CH3CCH gives the same answer. Propyne, CC#C, C3H4 ### CH2=CHCH2Cl The = sign fixes the double bond; Cl sits on the last CH2. 3-Chloroprop-1-ene (allyl chloride), C=CCCl ### C3H7OH C3H7 can be propyl or isopropyl. Ambiguous: propan-1-ol CCCO or propan-2-ol CC(C)O ## Limitations - Rings are read only through abbreviations (Ph, C6H5, C6H4, C6H11). A ring written atom by atom, such as cyclohexane as (CH2)6, is not closed. - Stereochemistry is never taken from a condensed formula. R/S and E/Z are left undefined, and the page says when they exist. - Molecular formulas (C2H6O, C6H12O6) and inorganic formulas such as H2SO4 or CuSO4·5H2O are not drawn. - Only one charge, written at the end, is read (for example CH3COO- or CH3NH3+), plus Na, K or Li salts. - The IUPAC name is looked up in PubChem and needs an internet connection. A structure that is not in PubChem gets no name. The drawing, SMILES, formula and masses are worked out in your browser. **Want to edit the structure?** Open it in MolDraw, the free online chemical structure editor, to add arrows, labels or stereo bonds. [Open MolDraw editor](https://www.moldraw.com/) ## Frequently asked questions ### How do I turn a condensed formula into a structure? Type it as you would write it, for example CH3COOCH2CH3, and press Draw structure. Each carbon is joined to the group written before it, H atoms and groups such as OH or Cl sit on the atom they follow, and double or triple bonds are added where the valences need them. CH3COOCH2CH3 gives ethyl acetate, CCOC(C)=O. ### What is the difference between a condensed formula and a molecular formula? A molecular formula only counts atoms: C2H6O. A condensed formula also shows how they are joined: CH3CH2OH is ethanol and CH3OCH3 is dimethyl ether, both C2H6O. Only a condensed formula (or a full structure) can be drawn. For a molecular formula, use the molecular formula to structure tool to list possible isomers. ### How are brackets read in formulas like (CH3)2CHCOOH or CH3(CH2)4CH3? A bracket with a number repeats the group. (CH3)2 at the start puts two methyl groups on the next carbon, so (CH3)2CHCOOH is 2-methylpropanoic acid. A group in brackets after an atom, as in CH3CH(NH2)COOH, is a branch on that atom. A unit with two free bonds, such as (CH2)4, is a chain: CH3(CH2)4CH3 is hexane. ### Why does the tool say my formula is ambiguous? Some formulas fit more than one molecule. C3H7OH can be propan-1-ol or propan-2-ol, and CH3C6H4OH can be the ortho, meta or para cresol. The tool shows every reading and does not pick one for you. Write the group out, for example CH3CH2CH2OH or (CH3)2CHOH, or add o-, m- or p- before a C6H4 formula. ### Does the condensed formula converter show stereochemistry? No. A condensed formula does not say which enantiomer or which cis/trans isomer is meant, so the structure is drawn without R/S or E/Z and the page tells you when a stereocentre or a stereogenic double bond is present. 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