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:
“As far as criticism is concerned, we don’t resent that unless it is absolutely biased, as it is in most cases.”
—John Vorster (1915–1983)
“A tailor can adapt to any medium, be it poetry, be it criticism. As a poet, he can mend, and with the scissors of criticism he can divide.”
—Franz Grillparzer (1791–1872)
“Nothing would improve newspaper criticism so much as the knowledge that it was to be read by men too hardy to acquiesce in the authoritative statement of the reviewer.”
—Richard Holt Hutton (1826–1897)