188540-76-3Relevant academic research and scientific papers
Asymmetric intramolecular [2 + 2] photocycloadditions: α- and β-hydroxy acids as chiral tether groups
Faure, Sophie,Piva-Le-Blanc, Sylvie,Bertrand, Cyrille,Pete, Jean-Pierre,Faure, Rene,Piva, Olivier
, p. 1061 - 1070 (2007/10/03)
Chiral α- and β-hydroxy acids such as (S)-lactic acid, (S)-phenyllactic acid, (S)-mandelic acid, or (3R)-3-hydroxybutyric acid have been used as tether groups for intramolecular and diastereoselective [2 + 2] photocycloaddition of 3-oxocyclohexene carboxylic acid derivatives. Total regiocontrol toward the straight adduct and high diastereoselectivities (up to 94%) were observed in the case of butenyl lactate 11. After separation of the two diastereoisomers, cleavage of the chiral tether under basic conditions afforded cyclobutane lactones in good yield and enantiomeric pure form. An X-ray structure has been recorded that confirmed the relative and absolute configuration of the three contiguous stereogenic centers assigned according to CD spectra.
Hydroxyacids as efficient chiral spacers for asymmetric intramolecular [2+2] photocycloadditions
Faure, Sophie,Piva-Le Blanc, Sylvie,Piva, Olivier,Pete, Jean-Pierre
, p. 1045 - 1048 (2007/10/03)
An indirect and efficient enantioselective [2+2] photocycloaddition between 3-carboxycyclohex-2-enone and allyl alcohol, involving a three step sequence, is described. When the reagents are linked by covalent bonds to a chiral spacer such as L-lactic or (R)-3-hydroxybutyric acids, the corresponding photocycloadducts are isolated in high yields, with very high regio and diastereoselectivities. The reaction affords polyfunctional cyclobutanes as pure enantiomers.
