Tandem and two-directional asymmetric catalysis of the Mukaiyama aldol reaction

✍ Scribed by Koichi Mikami; Satoru Matsukawa; Masako Nagashima; Hiroshi Funabashi; Hajime Morishima

• Book ID: 104256122
• Publisher: Elsevier Science
• Year: 1997
• Tongue: French
• Weight: 257 KB
• Volume: 38
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(96)02376-3

✦ Synopsis

Upon addition of an excess amount of an aldehyde 3, the Mukaiyama aldol reaction of a silyl enol ether 2 proceeds in tandem and two-directional fashion by the asymmetric catalysis of a binaphthol-derived chiral titanium complex (BINOL-Ti: 1) to give the silyl enol ether 4 in 77% isolated yield in more than 99% ee and 99% de. The present asymmetric catalytic Mukaiyama aldol reaction is characterized by amplification phenomena of the product chirality on going from the one-directional aldol intermediate 6 (98.5% ee, R) to the two-directional product 4 (99.6% ee, R,R). Further transformation of the pseudo C2 symmetric product 4 (> 99% ee, > 99% de) in its' protected form as the silyl enol ether is established leading to a potentially potent analogue of HIVP inhibitor 9a.