Criticism
In a 2007 paper Phil Baran notes that even though the textbooks state that the use of protective groups is unavoidable and that they are ideally easily added and removed, in practical terms in organic synthesis their use adds two synthetic steps (protection-deprotection sequence) to a chemical sequence and sometimes dramatically lowers chemical yield. Crucially, added complexity impedes the use of synthetic total synthesis in drug discovery. In contrast biomimetic synthesis does not employ protective groups. As an alternative, Baran presented a novel protective-group free synthesis of the compound hapalindole U. The previously published synthesis according to Baran, contained 20 steps with multiple protective group manipulations (two confirmed):
| Hapalindole U Baran 2007 protective-group free | Hapalindole U Muratake 1990 Ts protective groups in blue |
Read more about this topic: Protecting Groups
Famous quotes containing the word criticism:
“I am opposed to writing about the private lives of living authors and psychoanalyzing them while they are alive. Criticism is getting all mixed up with a combination of the Junior F.B.I.- men, discards from Freud and Jung and a sort of Columnist peep- hole and missing laundry list school.... Every young English professor sees gold in them dirty sheets now. Imagine what they can do with the soiled sheets of four legal beds by the same writer and you can see why their tongues are slavering.”
—Ernest Hemingway (1899–1961)
“To be just, that is to say, to justify its existence, criticism should be partial, passionate and political, that is to say, written from an exclusive point of view, but a point of view that opens up the widest horizons.”
—Charles Baudelaire (1821–1867)
“I hold with the old-fashioned criticism that Browning is not really a poet, that he has all the gifts but the one needful and the pearls without the string; rather one should say raw nuggets and rough diamonds.”
—Gerard Manley Hopkins (1844–1889)