Comments on: Eudesmane Terpenes

By: TotallySynthetic.com » Blog Archive » Polyanthellin A

TotallySynthetic.com » Blog Archive » Polyanthellin A — Tue, 14 Jul 2009 21:06:37 +0000

[...] standard proline-based catalyst, aided with a bit of a catechol to boost reaction rate and yield (another example is in this Baran paper). The remaining aldehyde was then Wittig’d to bolt-on a diene, and set them up for a bit of [...]

By: Finally…Total Synthesis: NOS Day 4 at C&ENtral Science

Finally…Total Synthesis: NOS Day 4 at C&ENtral Science — Tue, 16 Jun 2009 20:38:36 +0000

[...] concise syntheses of a family of terpenes from the eudesmane family. The syntheses in this work are cool in their own right, but make no mistake, this is a strategy paper for the Baran group. They’re thinking long [...]

By: stuffneverworksforme

stuffneverworksforme — Sat, 06 Jun 2009 21:11:58 +0000

Baran = god haha

By: bubu

bubu — Wed, 03 Jun 2009 15:37:18 +0000

really good,thanks

By: stuffneverworksforme

stuffneverworksforme — Wed, 03 Jun 2009 10:24:07 +0000

With regards to the Micrococcin P1, its only hot because the mystery of configuration was solved. The chemistry is well developed, the group already published the diastereomer years ago in organic letters, where the same methods where used.

By: LiqC

LiqC — Wed, 03 Jun 2009 07:39:49 +0000

Dioxiranes: I assume Shi would know (asymm. epoxidation)

Dissolving metals: well, not exactly metals and dissolving, but here’s something interesting – http://www.reakor.ru/alfa/Alkali_Metal-Silica_Gels.pdf

By: The Next Phil Baran

The Next Phil Baran — Fri, 29 May 2009 03:56:36 +0000

I am genuinely interested in that question. I’m trying to figure it out.

By: European Chemist

European Chemist — Thu, 28 May 2009 10:15:06 +0000

The paper is awesome by any standards – if not for the chemistry, especially for the thinking that goes underneath. The theoretical discussion is book-like, establishing concepts and stating very strong opinions.
Baran is the kind of chemist that annoys everyone, because he does NOT use any fancy chemistry nor exotic reagents. He just does things “a la Woodward” and relies on careful thinking rather than on pure brute force to complete his stuff. Of course, there are some students on the webpage that will probably never make it beyond 5th author on a single paper through their Ph.D. or Post-Doc, but looking at what stuff is successfully completed you can only imagine what other, wild projects are running in that group.

Particularly love the resorting to old chemistry: the dioxirane oxidations (which nobody really understands), the Hoffmann-Loffler chemistry (in which Baran himself has a hard time justifying the abnormal regioselectivity), the dissolving metal reduction of the ketone (it must have been at least 20 years since the last paper I read that reduced a ketone that way!!). You can still do a LOT of elegant stuff in academia without having to constantly follow “fashionable” trends (as he did on occasion by realising the value of an obvious, but never attempted organocatalytic asymmetric synthesis of cryptone).

By: The Next Phil Baran

The Next Phil Baran — Thu, 28 May 2009 09:23:30 +0000

I have been thinking about this paper quite a lot recently. I wonder if his rationalization about where the N-centered radical would react is correct, though I don’t doubt the result :->. To me it looks like the proton of the isopropyl group is inaccessible anyway (trans relationship, if it was cis it might happen.) Second, is it more likely that N-centered radicals would react at a carbon two bonds away or at a carbon adjacent to the carbamate group?

By: InfMP

InfMP — Sun, 24 May 2009 22:48:30 +0000

DMDO is stable indefinately in -80 fridge. I used to keep 0.1M for months and it never changed!