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, with other Americans, have perhaps unduly resented the stream of criticism of American life ... more particularly have I resented the sneers at Main Street. For I have known that in the cottages that lay behind the street rested the strength of our national character.”
—Herbert Hoover (1874–1964)
“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)
“A bad short story or novel or poem leaves one comparatively calm because it does not exist, unless it gets a fake prestige through being mistaken for good work. It is essentially negative, it is something that has not come through. But over bad criticism one has a sense of real calamity.”
—Rebecca West (1892–1983)