Chlorophenol and Ethylene Glycol

Diels-Alder Reaction in Non-Aqueous Polar Systems 

Spectroscopic measurements indicate that PCP forms hydrogen bonds with carbonyl oxygen atoms of cyclopentadienone in both the ground and transition states, but the transition state is more effectively stabilized than the ground state, so a rate enhancement is observed. 

Protic solvents such as i-PrOH and t-BuOH favor the diastereoselectivity of the reaction of 3-hydroxy-2-pyrone with acrylates [49b]. Further examples of proton-promoted Diels-Alder reactions are reported in Section 4.8. 

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The way in which organic compounds are bound within the hardened Portland cement paste, and their effect on hydration and the stmcture of the Itydrates formed, may vary greatly. Compounds that are insoluble in water usually have no effect, whereas those that are at least partially soluble may or may not slow down the rate of hydration, alter the stmcture of the hydrated paste, and decrease its strength. Compounds that exhibit an adverse effect on Portland cement hydration include various phenols, chlorophenols, and ethylene glycol, whereas metlianol or ethanol have almost no effect (Gmtzek, 1992). 

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