42945-18-6Relevant academic research and scientific papers
Acid-mediated intramolecular cationic cyclization using an oxygen atom as internal nucleophile: Synthesis of substituted oxazolo-, oxazino- and oxazepinoisoindolinones
Sikoraiová, Jana,Marchalín, ?tefan,Da?ch, Adam,Decroix, Bernard
, p. 4747 - 4751 (2007/10/03)
Efficient assembly of substituted oxazolo-, oxazino-, and oxazepinoisoindolinones (5-7, 12-15 and 19) is described in three steps according to an acidic α-oxoamidoalkylation reaction from ready available phthalic anhydride by successive imidation, sodium borohydride reduction and intramolecular cationic cyclization involving N-acyliminium species. The relative stereochemistry accompanying these reactions was also discussed.
Enantiopreference of Lipase from Pseudomonas cepacia toward Primary Alcohols
Weissfloch, Alexandra N. E.,Kazlauskas, Romas J.
, p. 6959 - 6969 (2007/10/03)
We propose an empirical rule that predicts which enantiomer of primary alcohol reacts faster in reactions catalyzed by lipase from Pseudomonas cepacia (PCL).This rule, based on the size of the substituents at the stereocenter, shows an 89percent reliability (correct for 54 of 61 examples).This rule is not reliable for primary alcohols that have an oxygen atom attached to the stereocenter; we excluded these alcohols from the tally above.Surprisingly, the sense of enantiopreference of PCL toward primary alcohols is opposit to its enantiopreference toward secondary alcohols.That is, the OH of secondary alcohols and the CH2OH of primary alcohols point in opposite directions.We suggest, however, that this opposite orientation does not imply a different position of the substituents in the active site of the lipase.Instead, PCL accommodates the extra CH2 in primary alcohols as a kink between the stereocenter and the oxygen which allows a similar position of the alcohols by increasing the diffrence in the size of the substituents but did not find a consistent increase in enantioselectivity.We suggest that high enantioselectivity toward primary alcohols requires not only a significant difference in the size of the substituents, but also control of the conformation along the C(1)-C(2) bond.
Synthesis of (R)- and (S)-2-Aminobutane from (S)- and (R)-2-Aminobutanol
Santaniello, Enzo,Casati, Rosangela,Milani, Fulvia
, p. 919 - 922 (2007/10/02)
(R)-(-)- and (S)-(+)-2-Aminobutane (1) can be synthesized in good yield and high optical purity from (S)-(+)- and (R)-(-)-2-aminobutanol (2) respectively.
