7462-38-6Relevant articles and documents
Diastereoselective Grignard Additions to O-Protected Polyhydroxylated Ketones: A Reaction Controlled by Groundstate Conformation?
Mulzer, Johann,Pietschmann, Catarina,Buschmann, Jürgen,Luger, Peter
, p. 3938 - 3943 (2007/10/03)
The O-protected polyhydroxy ketones 9-14 and 39, 42 add σ-type Grignard reagents with >90:10 stereoselectivity to give the 3,4-syn-adducts 17-22 and 43, 45, respectively, as the major diastereomers (Tables 1 and 2). The stereoselectivity is interpreted in terms of early transition states which are very close to the groundstate conformations shown in Figure 6 and 7. These demonstrate that the "top face" of the carbonyl group is much less shielded than the "bottom" face, Complexation phenomena are of minor importance. It is also shown that the classical transition state models (Felkin-Anh or chelate Cram) are not applicable to polyoxygenated ketones.
SYNTHESIS OF (3R,4R)-1,5-HEXADIEN-3,4,-DIOL AND ITS UNSYMMETRICAL DERIVATIVES : APPLICATION TO (R)-(+)-α-LIPOIC ACID
Rama Rao, A. V.,Mysorekar, S. V.,Gurjar, M. K.,Yadav, S. J.
, p. 2183 - 2186 (2007/10/02)
(3R,4R)-1,5-Hexadien-3,4-diol and its umsymmetrical derivatives were prepared starting from D-mannitol and their utility in the synthesis of (R)-(+)-α-lipoic acid has been explored.
