13103-40-7Relevant articles and documents
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Hurd,C.D.,Richardson,A.J.
, p. 3516 - 3520 (1967)
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An enzymatic domain for the formation of cyclic ethers in complex polyketides
Poeplau, Petra,Frank, Sarah,Morinaka, Brandon I.,Piel, Joern
, p. 13215 - 13218 (2013)
Champion cyclist: In vitro studies on the pederin biosynthetic pathway identify pyran synthases (PS) as a new family of polyketide synthase domains that stereoselectively form diverse five- and six-membered ether rings by oxa-conjugate cyclization during carbon-chain elongation. These domains could be useful tools for chemoenzymatic synthesis.
[3 + 2] Cycloreversion of Bicyclo[m.3.0]alkan-3-on-2-yl-1-oxonium Ylides to Alkenyloxyketenes. Stereospecific Aspect
Oku, Akira,Sawada, Yuichi,Schroeder, Marc,Higashikubo, Ichiro,Yoshida, Tomohiro,Ohki, Shigeji
, p. 1331 - 1336 (2007/10/03)
Rhodium(II)-catalyzed intramolecular reaction of diazoketones 1 bearing a cyclic ethereal moiety transiently formed bicyclo[m.3.0]octan-3-one-1-oxonium-2-ylides (2), which underwent sigmatropic and stereospecific [3 + 2] cycloreversion reaction to form alkenyloxyketenes 3. The ketenes were efficiently trapped by methanol to form the corresponding esters 4. Mechanistic studies revealed that the size of ethereal ring can be variable at least from THF to the THP, oxepane, and oxocane moiety, i.e., m = 3-6. On the other hand, the size of the ylide ring containing the carbonyl unit is limited to a five-membered ring. The cycloreversion was found to be stereospecific as was proven by the reactions of diastereoisomeric pairs bearing a methyl group at the bond-cleaving position. From threo isomers 7, (E)-alkenyloxyacetates 15 were exclusively formed (77-84%), whereas from erythro isomers 8, (Z)-isomers 16 were formed (80-88%). Mechanism of the cleavage from diazoacetonyl-substituted cyclic ethers to alkenyloxyketenes via bicyclic oxonium ylides was analyzed on the basis of calculations employing the hybrid density functional B3LYP and the highly correlated quadratic configuration interaction QCISD method to reveal that the concerted [3 + 2] cycloreversion is the key step of this reaction.
SYSTHESIS AND INTRAMOLECULAR RING CLEAVAGE OF 2-OXETANONES
Mead, Keith T.,Samuel, Beverly
, p. 6573 - 6576 (2007/10/02)
Intermolecular 2+2 aldehyde-ketene cycloaddition, followed by Lewis acid induced intramolecular ring opening of the 2-oxetanone product have been used to prepare tetrahydrofuran and tetrahydropyran ring systems.