New chiral auxiliaries: their use in the asymmetric hydrogenation of .beta.-acetamidocrotonates
作者:Dominique Potin、Francoise Dumas、Jean D'Angelo
DOI:10.1021/ja00165a036
日期:1990.4
Synthesis of chiral β-amido esters with high diastereoisomeric excess was achieved by asymmetric hydrogenation (H 2 /PtO 2 ) of stereogenic β-acetamidocrotonates in which the chirality is present in the alkyl of the ester part. For such a purpose, new efficient chiralauxiliaries such as 2,2-diphenylcyclopentanol and 1,1-diphenyl-3-methyl-2-butanol were developed
Reductive opening of 2-phenyl-1,3-dioxolanes by a naphthalene-catalysed lithiation: synthetic applications
作者:Juan F. Gil、Diego J. Ramón、Miguel Yus
DOI:10.1016/s0040-4020(01)80223-4
日期:——
The reaction of 2-phenyl-1,3-dioxolanes 1a,b with an excess of lithium powder in the presence of a catalytic amount of naphthalene (4 mol %) in tetrahydrofuran at -40-degrees-C followed by successive reaction with an electrophile and final hydrolysis with water at the same temperature yields the corresponding monoprotected 1,2-diols 2aa-2bf. The same process but allowing to rise the temperature to 20-degrees-C before the hydrolysis affords alcohols 3aa-3bd. The use of 2,2-diphenyl-1,3-dioxolane 1d, under similar reaction conditions as for compounds 2, permits the isolation of 2,2-diphenylalcohols 11da-11dc, resulting from the reaction with two different electrophiles. A mechanistic rationalization for all processes is given.
Danilow, Zhurnal Russkago Fiziko-Khimicheskago Obshchestva, 1920, vol. 52, p. 415
作者:Danilow
DOI:——
日期:——
POTIN, DOMINIQUE;DUMAS, FRANCOISE;DANGELO, JEAN, J. AMER. CHEM. SOC., 112,(1990) N, C. 3483-3486
作者:POTIN, DOMINIQUE、DUMAS, FRANCOISE、DANGELO, JEAN