pinacoln.
/ˈpɪnəkɒl/, U.S. /ˈpɪnəˌkɔl/, /ˈpɪnəˌkɑl/ Chemistry.
An alcohol having two hydroxyl groups bonded to adjacent tertiary carbon atoms; spec. the simplest alcohol of this kind, 1,4-dimethylpropan-2,3-diol (also called tetramethyl ethylene glycol), (CH3)2(OH)C—C(OH)(CH3)2, a crystalline solid made by reducing acetone with magnesium amalgam. Cf. pinacone n.
ΘΚΠ
the world > matter > chemistry > organic chemistry > alcohols > [noun] > dihydric alcohols or glycols > pinacol
pinacone1866
pinacol1911
1911 Chem. Abstr. 5 3561 The solid pinacols have normal mol. wts. in dil. C6H6.
1912 Chem. Abstr. 6 82 The fraction b. 214° of the products of hydrolysis of crude pinacol by H2SO4.
1932 Jrnl. Amer. Chem. Soc. 54 3275 Oxonium salts of pinacol are prepared and a mechanism for the rearrangement is proposed.
1981 P. Sykes Guidebk. to Mechanism in Org. Chem. (ed. 5) v. 115 This is demonstrated by taking, for example, two pinacols..that are very similar in structure (and that rearrange at very much the same rate) but that have different migrating groups.
2001 School Sci. Rev. Sept. 55/2 The modified reaction worked, and in no time 3,3,4,4-tetramethyl dioxetane..came into existence as yellow crystals that readily sublimed like pinacol.
Compounds
pinacol rearrangement n. a reaction typified by the conversion of pinacol into pinacolone, in which a 1,2-glycol loses water on heating with acid to form a ketone.
ΘΚΠ
the world > matter > chemistry > organic chemistry > chemical processes or reactions > [noun] > miscellaneous other
biuret reaction1883
condensation1886
semidine reaction1893
pinacol rearrangement1920
formylation1930
hydrogenolysis1931
polyamidation1946
ene reaction1969
1920 Jrnl. Amer. Chem. Soc. 42 796 The facility of the pinacol rearrangement indicates that the steric hindrance to transmigration is slight.
1966 L. O. Smith & S. J. Cristol Org. Chem. xiii. 289 The pinacol rearrangement is quite general for glycols in which all four groups..are alkyl or aryl groups.
1999 Jrnl. Org. Chem. 64 1508 The first pathway-specific transformation..is a tandem pinacol rearrangement/reduction.
This entry has been updated (OED Third Edition, June 2006; most recently modified version published online March 2022).
<
n.1911