104947-69-5Relevant articles and documents
The development of a convergent and efficient enantioselective synthesis of the bengamides via a common polyol intermediate
Boeckman Jr., Robert K.,Clark, Tammy J.,Shook, Brian C.
, p. 4532 - 4560 (2007/10/03)
An efficient, general synthetic route to the bengamide family of antitumor agents from a common polyol thioester is described. Consecutive aldol condensations afford the protected polyol thioester side chain suitable for coupling to the bengamides. A novel chiral-phase-transfer-catalyzed enantioselective alkylation affords the properly functionalized caprolactams required for the synthesis of more-complex members of the bengamide family. Use of the methyl 2-naphthyl ether protecting group, compatible with the boron Lewis acids required for enantioselective aldol condensation, allows direct access to all the bengamides.
Total syntheses of bengamides B and E
Kinder, Jr.,Wattanasin,Versace,Bair,Bontempo,Green,Lu,Marepalli,Phillips,Roche,Tran,Wang,Waykole,Xu,Zabludoff
, p. 2118 - 2122 (2007/10/03)
Total syntheses of the cytotoxic marine natural products bengamides B and E are described. Both bengamides are prepared via amide coupling of a protected polyhydroxylated lactone intermediate 9 with a suitably substituted aminocaprolactam intermediate. Lactone 9 is prepared in five steps from commercially available α-D-glucoheptonic γ-lactone. The key reactions are a selective deprotection of a 1,2-acetonide in the presence of a 1,3-acetonide and an (E)-selective olefination of an unstable aldehyde using a gem-dichromium reagent. The bengamide B lactam intermediate 10 is prepared in seven steps from commercially available (5R)-5-hydroxy-L-lysine (12). The desired S-configuration at the γ-OH lactam position is established using the Mitsunobu reaction.
Enantioselective total syntheses of bengamides B and E
Broka,Ehrler
, p. 5907 - 5910 (2007/10/02)
Convergent total syntheses of two sponge-derived cyclolysine derivatives - bengamides B (1) and E (2) - have been accomplished. The polyhydroxylated side chain common to both natural products was obtained from L-glucose and the hydroxylated caprolactam moiety of 1 was prepared using Evans' oxazolidinone chemistry. In the course of this work a new Horner-Emmons reagent incorporating one of Evans' chiral auxiliaries was developed.
