Alkyne-alcohols, dehydration hydration

Moving one step further back in the synthetic sequence towards cyclopentenoftes identifies the alkynic alcohols as viable precursors. Since the subsequent dehydration-hydration-cyclization steps are all acid-... 

Alkenes and alkynes obviously don t fit easily into these categories as they have no bonds to heteroatoms. Aikenes can be made from alcohols by dehydration without any oxidation or reduction so it seems sensible to put them in the alcohol column. Similarly, alkynes and aldehydes are related by hydration/dehydration without oxidation or reduction. 

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