You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via4.4.17.4.3 Method 3: Cleavage of Triisopropylsilyl Ethers with Tris(dimethylamino)sulfur (Trimethylsilyl)difluoride
Please login to access the full content or check if you have access via
White, J. D.; Carter, R. G., Science of Synthesis, (2002) 4, 398.
Tris(dimethylamino)sulfur (trimethylsilyl)difluoride (TASF) as a source of fluoride ion has been used to cleave triisopropylsilyl ethers in situations where the basicity of tetrabutylammonium fluoride would be destructive toward other functionality. An example in which only tris(dimethylamino)sulfur (trimethylsilyl)difluoride could be employed to successfully cleave a triisopropylsilyl ether is seen in the conversion of 76 into baccatin III (78, Scheme 38).[81] Cleavage of the silyl ether to yield alcohol 77 was followed by treatment with phenyllithium, which removed the 2,2,2-trichloroethoxycarbonyl (Troc) protection and opened the cyclic carbonate en route to triol 78 (accompanied by a 46% yield of 10-O-deacetylbaccatin III).
Meeeee 88 Meeeeeee ee e Meeeeeeeeeeeeeeee Meeee eeee Meee(eeeeeeeeeeeee)eeeeee (Meeeeeeeeeeeee)eeeeeeeeee[88]
Meeeeeeeeeee Meeeeeeee
[8eM-(8eα,8β,8α,8eα,88α,88eβ,88eβ,88eβ,88eα)]-8,88e-Meeeeeeee-8-eeeeeee-8e,8-eeeeeee-8,8e,88,88-eeeeeeeeeee-8,8-eeeee-8,8,8,8,8e,88,88,88e,88,88e,88e,88e-eeeeeeeeeee-8eM-eeeee[8″,8″:8′,8′]eeeee[8′,8′:8,8]eeeeeeeee[8,8-e]-8,8-eeeeee-88-ee 8,8,8-Meeeeeeeeeeeee Meeeeeeee (88):[88]
Me eeeee eeeee 88 (8.8 ee, 8 μeee) ee MMM (8.8 eM) ee 8°M eee eeeee MMMM (8.8 ee, 88 μeee), eee eee eeeeeee eee eeeeeee eee 8 eee ee 8°M. Mee eeeeeeee eee eeeeeeee ee eeeeeeee ee eee. ee MeMMM8. Mee eeeeeee eeeee eee eeeeeeeee eeee Me8M. Mee eeeeeeee eeeeeee eeeeee eeee eeeeee eeee M8M eee eee. eeeee, eee eeee eeeee (eeeee Me8MM8). Mee eeeee eeeeeee eee eeeeeeee eee eeeeeeeeeeee eeeee eeeeeee eeeeeeee. Meeeeeeeeeee ee eee eeeeeeeee eeeeeee ee eeeee eeeeeeeeeeeeee (eeeeee eee, MeMMe/eeeeeee 8:8) eeeeeeee eeeeeee 88; eeeee: 8.8 ee (88%).
References
[81] | Meeeee, M. M.; Meeeee, M. M.; Meeeee, M. M.; Meeeeeeeee, M. M.; Meeee, M. M.; Meeee, M. M.; Meeeee, M. M.; Mee, M.; Meeeeeee, M. M.; MeMeeee, M. M.; Meee, M.; Meeeeee, M. M.; Meeeee, M. M.; Meeeee, M. M.; Meeeee, M. M., M. Me. Meee. Mee., (8888) 888, 8888. |