A spaced-repetition system with a syllabus

Remember what you read. In order.

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Organic chemistry · SN2

Why does an SN2 reaction invert the stereocentre?

AnswerSource: Clayden, ch. 15

The nucleophile attacks from the back side, opposite the leaving group, flipping the other three bonds like an umbrella in the wind.

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§1 How it works

Five ideas, kept strictly.

  1. Notetypes you design

    Fields and templates are yours. A note becomes whichever cards its template describes.

  2. A protocol with a paper trail

    Scheduling runs on one versioned protocol. Every revision is kept.

  3. Sessions that hold still

    Cards are seated when you begin, so the session you start is the one you finish.

  4. Footnotes on every card

    Notes cite their sources, down to the chapter or page.

  5. A history that isn't edited

    Reviews are immutable events: the record of what you learned, and when.

Organic chemistry: Atoms & bonds, Electronegativity and Stereochemistry are mastered, which opens Acids and SN2; E2 and Synthesis stay locked until SN2 is masteredAtoms & bondsElectronegativityStereochemistryAcidsSN2E2 · lockedSynthesis

§2 Skill trees

A syllabus that knows what you know.

Each tree is a subject; each node, a concept holding your notes. Prerequisites keep a node closed until its foundations are mastered, then its new cards join your reviews. One note can sit in many nodes, and every review counts toward each.

§3 For developers & agents

Bring your own assistant.

Everything in Lectro is an API call. Connect the MCP server and your AI assistant can read alongside you, draft notes with citations, file them into the right nodes and run a session when you’re ready.

Read the API reference →
curl https://app.lectro.ai/api/v1/notes \
  -H "Authorization: Bearer crt_…" \
  -H "Content-Type: application/json" \
  -d '{
    "notetype_id": "…",
    "fields": {
      "Front": "Why does SN2 invert?",
      "Back": "Back-side attack."
    },
    "node_ids": ["…"]
  }'

§4 Pricing

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