Organocatalytic α-hydroxymethylation of cyclopentanone with aqueous formaldehyde: Easy access to chiral δ-lactones
摘要:
Optically active lactones are important synthons in perfume and aroma manufacturing. Therefore, developments of efficient asymmetric syntheses are desired. Organocatalytic asymmetric alpha-hydroxymethylations of cyclopentanone with aqueous formaldehyde have been developed, to furnish the corresponding alpha-(hydroxymethyl) cyclopentanone with high enantioselectivity. Further chemical transformation of alpha-(hydroxymethyl) cyclopentanone gave the key intermediate for jasmine lactone, which is widely found in fruits and flowers. (C) 2009 Elsevier Ltd. All rights reserved.
Optically active lactones are important synthons in perfume and aroma manufacturing. Therefore, developments of efficient asymmetric syntheses are desired. Organocatalytic asymmetric alpha-hydroxymethylations of cyclopentanone with aqueous formaldehyde have been developed, to furnish the corresponding alpha-(hydroxymethyl) cyclopentanone with high enantioselectivity. Further chemical transformation of alpha-(hydroxymethyl) cyclopentanone gave the key intermediate for jasmine lactone, which is widely found in fruits and flowers. (C) 2009 Elsevier Ltd. All rights reserved.
Direct asymmetric α-hydroxymethylation of ketones in homogeneous aqueous solvents
A chiral prolinamide-based zinc complex promotes the aldol reaction of ketones with aqueous formaldehyde, giving the corresponding adducts in good yields and high ees. The efficient direct aldol reaction of formaldehyde with ketones in homogeneous aqueous solution is presented for the first time. (C) 2010 Elsevier Ltd. All rights reserved.