science

Longifolene

Longifolene is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Longifolene rather than just read about it. In short: Longifolene is a common sesquiterpene. It is an oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins.

Key takeaways

Longifolene belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Longifolene to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Longifolene from memory before moving on to harder problems.

Reference excerpt

Longifolene is a common sesquiterpene. It is an oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins. The name is derived from that of a pine species from which the compound was isolated. It is a tricyclic chiral molecule. The enantiomer commonly found in pines and other higher plants exhibits a positive optical rotation of +42.73°. The other enantiomer (optical rotation −42.73°) is found in small amounts in certain fungi and liverworts.

Occurrence Terpentine obtained from Pinus longifolia (obsolete name for Pinus roxburghii Sarg.) contains as much as 20% of longifolene. Longifolene is also one of two most abundant aroma constituents of lapsang souchong tea, because the tea is smoked over pinewood fires.

Biosynthesis The biosynthesis of longifolene begins with farnesyl diphosphate (1) (also called farnesyl pyrophosphate) by means of a cationic polycyclization cascade. Loss of the pyrophosphate group and cyclization by the distal alkene gives intermediate 3, which by means of a 1,3-hydride shift gives intermediate 4. After two additional cyclizations, intermediate 6 produces longifolene by a 1,2-alkyl migration.

Synthesis and related chemistry The laboratory characterization and synthesis of longifolene has long attracted attention.

It reacts with borane to give the derivative dilongifolylborane, which is a chiral hydroborating agent.

References

External links Longifolene Total Syntheses @ SynArchive.com

Illustrations

Worked examples

Example 1 — a first encounter with Longifolene

Start with the simplest possible case. Write down what Longifolene claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Longifolene before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Longifolene ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Longifolene

In research: Longifolene appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Longifolene in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Longifolene is common in secondary-school and first-year university syllabi. It links to neighbouring topics Polycyclic nonaromatic hydrocarbons, Sesquiterpenes, Total synthesis, so understanding it makes those chapters shorter.
In everyday life: Look for Longifolene outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Longifolene in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Longifolene means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Longifolene out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Longifolene in simple terms?

Longifolene is a common sesquiterpene. It is an oily liquid hydrocarbon found primarily in the high-boiling fraction of certain pine resins.

Why does Longifolene matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Longifolene?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Longifolene.