Mechanism of the acid-catalyzed double bond migration in 3-cyclohexen-1-one and 3-methyl-3-cyclohexen-1-one

1972 ◽  
Vol 37 (3) ◽  
pp. 394-397 ◽  
Author(s):  
Donald S. Noyce ◽  
Malcolm. Evett
Author(s):  
Hideharu Seto ◽  
Shozo Fujioka ◽  
Hiroyuki Koshino ◽  
Suguru Takatsuto ◽  
Shigeo Yoshida

1976 ◽  
Vol 98 (22) ◽  
pp. 7102-7104 ◽  
Author(s):  
Paul A. Grieco ◽  
Mugio Nishizawa ◽  
Nebojsa Marinovic ◽  
William J. Ehmann

ChemInform ◽  
2010 ◽  
Vol 25 (8) ◽  
pp. no-no
Author(s):  
F. M. DEAN ◽  
M. MALKI ◽  
L. J. O'KEEFFE

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Liujuan Zheng ◽  
Haowen Wang ◽  
Aili Fan ◽  
Shu-Ming Li

Abstract Oxepinamides are derivatives of anthranilyl-containing tripeptides and share an oxepin ring and a fused pyrimidinone moiety. To the best of our knowledge, no studies have been reported on the elucidation of an oxepinamide biosynthetic pathway and conversion of a quinazolinone to a pyrimidinone-fused 1H-oxepin framework by a cytochrome P450 enzyme in fungal natural product biosynthesis. Here we report the isolation of oxepinamide F from Aspergillus ustus and identification of its biosynthetic pathway by gene deletion, heterologous expression, feeding experiments, and enzyme assays. The nonribosomal peptide synthase (NRPS) OpaA assembles the quinazolinone core with d-Phe incorporation. The cytochrome P450 enzyme OpaB catalyzes alone the oxepin ring formation. The flavoenzyme OpaC installs subsequently one hydroxyl group at the oxepin ring, accompanied by double bond migration. The epimerase OpaE changes the d-Phe residue back to l-form, which is essential for the final methylation by OpaF.


2010 ◽  
Vol 5 (5) ◽  
pp. 1934578X1000500
Author(s):  
Jixun Zhan ◽  
E. M. Kithsiri Wijeratne ◽  
A. A. Leslie Gunatilaka

Biotransformation of monocillin I (1) by Beauveria bassiana ATCC 7159 was investigated. Two new derivatives 2 and 3 were isolated and identified on the basis of the spectroscopic data. Compounds 2 and 3 are synthesized by hydration at 10,11-double bond and hydrolysis of 14,15-epoxide, respectively. The R configuration of 11-OH in 2 was established by the modified 2-methoxy-2-trifluoromethylphenylacetic acid (MTPA) method. The conversion of 1 to 2 and 3 was reconstituted in an acid solution, indicating that the formation of 2 and 3 is an acid-catalyzed instead of an enzymatic process.


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