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:
“It is the will of God that we must have critics, and missionaries, and Congressmen, and humorists, and we must bear the burden. Meantime, I seem to have been drifting into criticism myself. But that is nothing. At the worst, criticism is nothing more than a crime, and I am not unused to that.”
—Mark Twain [Samuel Langhorne Clemens] (1835–1910)
“When you overpay small people you frighten them. They know that their merits or activities entitle them to no such sums as they are receiving. As a result their boss soars out of economic into magic significance. He becomes a source of blessings rather than wages. Criticism is sacrilege, doubt is heresy.”
—Ben Hecht (1893–1964)
“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)