Lipase-catalyzed domino kinetic resolution/intramolecular Diels-Alder reaction: one-pot synthesis of optically active 7-oxabicyclo[2.2.1]heptenes from furfuryl alcohols and beta-substituted acrylic acids.
The first lipase-catalyzed domino reaction is described in which the acyl moiety formed during the enzymatic kinetic resolution of furfuryl alcohols (+/-)-3 with a 1-ethoxyvinyl ester 2 was utilized as a part of the constituent structure for the subsequent Diels-Alder reaction. The preparation of ester 2 from carboxylic acid 1 and the subsequent domino reaction were carried out in a one-pot reaction. Therefore, this procedure provides a convenient preparation of the optically active 7-oxabicyclo[2.2.1]heptene derivatives 5, which has five chiral, non-racemic carbon centers, from achiral 1 and racemic 3. The overall efficiency of this process was dependent on the substituent at the C-3 position of 3, and the use of the 3-methylfurfuryl derivatives, (+/-)-3 b and (+/-)-3 f, exclusively produced diastereoselectivity with excellent enantioselectivity to give (2R)-syn-5 (91->/=99 % ee) and (S)-3 (96->/=99 % ee). Similar procedures starting from the 3-bromofurfuryl alcohols (+/-)-3 h-j provided the cycloadducts (2R)-syn-5 j-q (93->/=99 % ee), in which the bromo group was utilized for the installation of bulky substituents to the 7-oxabicycloheptene core.
Akai
Shuji
S
Graduate School of Pharmaceutical Sciences Osaka University 1-6, Yamadaoka, Suita, Osaka 565-0871, Japan.
Naka
Tadaatsu
T
Omura
Sohei
S
Tanimoto
Kouichi
K
Imanishi
Masashi
M
Takebe
Yasushi
Y
Matsugi
Masato
M
Kita
Yasuyuki
Y
D000179:Acrylates / Q000737:chemistry*; D001643:Bridged Bicyclo Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D002384:Catalysis; D004952:Esters / Q000737:chemistry; D005663:Furans / Q000737:chemistry*; D007700:Kinetics; D008049:Lipase / Q000378:metabolism*; D011549:Pseudomonas / Q000201:enzymology; D013237:Stereoisomerism
D000179:Acrylates; D001643:Bridged Bicyclo Compounds; D004952:Esters; D005663:Furans; C012986:furfuryl alcohol; D008049:Lipase; C036658:acrylic acid