- CYP505E3: A Novel Self-Sufficient ω-7 In-Chain Hydroxylase
-
The self-sufficient cytochrome P450 monooxygenase CYP505E3 from Aspergillus terreus catalyzes the regioselective in-chain hydroxylation of alkanes, fatty alcohols, and fatty acids at the ω-7 position. It is the first reported P450 to give regioselective in-chain ω-7 hydroxylation of C10–C16 n-alkanes, thereby enabling the one step biocatalytic synthesis of rare alcohols such as 5-dodecanol and 7-tetradecanol. It shows more than 70 percent regioselectivity for the eighth carbon from one methyl terminus, and displays remarkably high activity towards decane (TTN≈8000) and dodecane (TTN≈2000). CYP505E3 can be used to synthesize the high-value flavour compound δ-dodecalactone via two routes: 1) conversion of dodecanoic acid into 5-hydroxydodecanoic acid (24 percent regioselectivity), which at low pH lactonises to δ-dodecalactone, and 2) conversion of 1-dodecanol into 1,5-dodecanediol (55 percent regioselectivity), which can be converted into δ-dodecalactone by horse liver alcohol dehydrogenase.
- Maseme, Mpeyake Jacob,Opperman, Diederik Johannes,Pennec, Alizé,Smit, Martha Sophia,van Marwijk, Jacqueline
-
supporting information
p. 10359 - 10362
(2020/04/23)
-
- Ketyl-type radicals from cyclic and acyclic esters are stabilized by SmI2(H2O)n: the role of SmI2(H 2O)n in post-electron transfer steps
-
Mechanistic details pertaining to the SmI2-H2O- mediated reduction and reductive coupling of 6-membered lactones, the first class of simple unactivated carboxylic acid derivatives that had long been thought to lie outside the reducing range of SmI2, have been elucidated. Our results provide new experimental evidence that water enables the productive electron transfer from Sm(II) by stabilization of the radical anion intermediate rather than by solely promoting the first electron transfer as originally proposed. Notably, these studies suggest that all reactions involving the generation of ketyl-type radicals with SmI2 occur under a unified mechanism based on the thermodynamic control of the second electron transfer step, thus providing a blueprint for the development of a broad range of novel chemoselective transformations via open-shell electron pathways.
- Szostak, Michal,Spain, Malcolm,Procter, David J.
-
supporting information
p. 8459 - 8466
(2014/06/24)
-
- SYNTHESIS OF 2-SUBSTITUTED TETRAHYDROFURANS
-
We have developed a three-stage scheme for the preparative synthesis of 2-substituted tetrahydrofurans from allyl halides and aldehydes to give the first stage - a Grignard reaction - mixed alkoxides, which on treatment with acetic anhydride are converted to 4-acetoxy-1-alkenes.Addition of hydrogen bromide to the latter contrary to Markownikoff's rule gives 4-acetoxy-1-bromoalkanes, which as a result of hydrolysis form 2-R-tetrahydrofurans.
- Volynskii, N. P.,Perepelitchenko, L. I.
-
p. 1324 - 1327
(2007/10/02)
-