200499-58-7Relevant articles and documents
Synthesis of new pyrrolidine-based organocatalysts and study of their use in the asymmetric Michael addition of aldehydes to nitroolefins
Castán, Alejandro,Badorrey, Ramón,Gálvez,Díaz-De-Villegas
, p. 612 - 619 (2017/06/20)
New pyrrolidine-based organocatalysts with a bulky substituent at C2 were synthesized from chiral imines derived from (R)-glyceraldehyde acetonide by diastereoselective allylation followed by a sequential hydrozirconation/iodination reaction. The new compounds were found to be effective organocatalysts for the Michael addition of aldehydes to nitroolefins and enantioselectivities up to 85% ee were achieved.
Enantiospecific syntheses of (R)- and (S)-proline and some derivatives from D-glucono-1,5-lactone
Mazzini, Claudio,Sambri, Letitia,Regeling, Henk,Zwanenburg, Binne,Chittenden, Gordon J. F.
, p. 3351 - 3356 (2007/10/03)
Carbohydrate-based enantiospecific syntheses of (R)-proline 1 and (S)-proline 2 from the previously reported D-erythro-hexonate ester 9 are described. Azide-substitution reactions on appropriately activated intermediates derived from ester 9, followed by reductive cyclization (H2/Pd-C), gave the substituted pyrrolidines 14 and 22, which were converted into their corresponding N-Cbz derivatives 16 and 24 in conventional manner. Mild acidic hydrolysis of these, followed by oxidation (sodium metaperiodate), gave the protected prolinals 3 and 4, which on further oxidation (sodium chlorite), followed by catalytic hydrogenolysis, gave the prolines 1 and 2. The N-Cbz-prolinol derivatives 5 and 6 are also reported.