tag:blogger.com,1999:blog-51846086760422068.post5327814900389959305..comments2024-03-28T08:37:08.964-07:00Comments on Open Flask: Phorbol SynthesisBaranLabhttp://www.blogger.com/profile/01806245988209508968noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-51846086760422068.post-16469586150299886602016-07-08T16:43:00.503-07:002016-07-08T16:43:00.503-07:00Congratulations! I think it’s a great work.
I hav...Congratulations! I think it’s a great work.<br /><br />I have one thing I’d like to ask you.<br />Going from compound 15 to 16, how do you rationalize the stereoselectivity at C10?anchemhttps://www.blogger.com/profile/18007845875496321019noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-74982193632045867442016-04-15T18:14:06.624-07:002016-04-15T18:14:06.624-07:00I started with conditions for ketohydroxylation of...I started with conditions for ketohydroxylation of olefins (Plietker, B. Eur. J. Org. Chem. 2005, 1919-1929.). Then, conditions were optimized as you can see above. It's only showing part of it but various oxidants were screened to find a suitable oxidation state of the ruthenium for this reaction. NaBrO3 is used for preparing TPAP from RuCl3 so I was assuming that the active species would be Ru (Vll) but we didn't do any mechanistic studies. Also, it's really important to have homogeneous reaction mixture. Once the water layer is separated from the organic layer, you will see different products. This might be because of the C-C bond cleavage though I didn't analyze these byproducts very closely (at least they were not simple aldehydes or carboxylic acids). In some conditions, I also detected C-C bond cleavage on the side chain (forming methyl ketone). Anyway, this reaction was really clean as long as the optimized conditions were used, which didn't even require column purification.<br /><br />-ShuheiShuhei Kawamurahttps://www.blogger.com/profile/05298186479383859521noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-86198558888890983982016-04-12T21:49:36.778-07:002016-04-12T21:49:36.778-07:00Sorry for double-posting.
One thing I wanted to a...Sorry for double-posting.<br /><br />One thing I wanted to ask you is how you came up with the oxidizer for RuCl3. <br /><br />Typically, one would use periodate as the terminal oxidant in RuCl3 catalyzed oxidations, which leads to RuO4, and this is a pretty nonselective vigorous oxidant (that can take methoxyphyphenyl group down to a carboxyl). <br /><br />NaBrO3 is presumably a milder reagent, I liked it for oxidation of thiols to disulphides and benzylic alcohols to acetophenones. Please do you have an isight, or was it a lit precedent/a stroke of luck? Does it produce a different oxidation state of Ru - i.e. Ru(VII)?<br /><br />milkshakehttps://www.blogger.com/profile/08188961610554710616noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-23064083862256338792016-04-12T21:45:54.584-07:002016-04-12T21:45:54.584-07:00This comment has been removed by the author.milkshakehttps://www.blogger.com/profile/08188961610554710616noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-24178910542819542012016-04-12T21:45:14.162-07:002016-04-12T21:45:14.162-07:00This comment has been removed by the author.milkshakehttps://www.blogger.com/profile/08188961610554710616noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-86497865695925028942016-03-31T09:10:42.020-07:002016-03-31T09:10:42.020-07:00This comment has been removed by the author.Anonymoushttps://www.blogger.com/profile/10236956552442937854noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-91321640366043694272016-03-31T02:59:06.827-07:002016-03-31T02:59:06.827-07:00Feed Burner doesn't work any more..
"Back...Feed Burner doesn't work any more..<br />"Back to Heterocycles!" is the latest article.<br />Have some ideas?hmmmhttps://www.blogger.com/profile/07212225886647957972noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-25546631104473001402016-03-24T12:58:57.038-07:002016-03-24T12:58:57.038-07:00Thanks so much Mauro!Thanks so much Mauro!BaranLabhttps://www.blogger.com/profile/01806245988209508968noreply@blogger.comtag:blogger.com,1999:blog-51846086760422068.post-80946951368326859072016-03-24T10:21:43.677-07:002016-03-24T10:21:43.677-07:00Really nice piece of work.
I always enjoy reading ...Really nice piece of work.<br />I always enjoy reading your blog posts almost as much as reading your papers, keep it up!<br />Best,<br />MauroBlogMasterhttps://www.blogger.com/profile/11589941180709457918noreply@blogger.com