Navigation

0 Hits

  • Previous / Next

You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via
36.12.9.1.3.1 Variation 1: Retro-Brook Rearrangements

DOI: 10.1055/sos-SD-036-00789

Morey, J. V.; Wheatley, A. E. H.Science of Synthesis, (2008361130.

Brook rearrangements and the reverse process, the retro-Brook rearrangement (trialkylsilyl migration from trialkylsilyl ethers to carbanion centers), have been thoroughly studied.[‌56‌] Retro-Brook transmetalation has been found to proceed in an intramolecular fashion without radical formation, driven by formation of the most stable alcoholate. In contrast to the inversion of configuration noted when rearrangement occurs in aryl-substituted compounds,[‌57‌,‌58‌] configuration is retained at the migratory terminus during the aliphatic retro-Brook process.[‌59‌] Exploration of the ring-closure of 4-(tert-butyldimethylsiloxy)hex-5-enyllithium has revealed that [2-(tert-butyldimethylsiloxy)cyclopentyl]methyllithium (91) undergoes facile retro-[1,4]-Brook rearrangement only in the syn-form to give lithium alcoholate 92, which on reaction with methanol gives the alcohol 93 (Scheme 33).[‌60‌]

Meeeee 88 Meeee-[8,8]-Meeee Meeeeeeeeeeee[‌88‌]

Meeeeeeeeeee Meeeeeeee

(8M,8M)-8-[(eeee-Meeeeeeeeeeeeeeeee)eeeeee]eeeeeeeeeeeee (88); Meeeeee Meeeeeeee:[‌88‌]

MMMMMMM: M 8 M eeeeeeee ee eeee-eeeeeeeeeeee ee eeeeeee eeeeeee ee eeeee eee eee eeeeee eeeeeeeeeee eeee eeeee.

M ee. 8.8M eeee ee eee-8-(eeeeeeeeee)-8-(eeee-eeeeeeeeeeeeeeeeeee)eeeeeeeeeeee ee eeeeeee/Me8M (8:8 ee eeeeee) eeeeeeeeee ee eeeeeeeeee eeeeeee eeeeee ee eeeeeee eeeeeeee eeeeeeee eee eeeeeee ee 88°M, eeeeeeeee e-MeMe (8.8 eeeee) ee eeeeeee eee eeeee eeeeeeee eeee 8eee. Mee eeeeeeeee eeeeeee eee eeeeeee eee 8eee ee eeee eeeeeeeeeee, eeeeee eee MMMMM (8.8 eeeee) eee eeeee ee eeeeeee ee eeee eeeeeee eeeeeeeeee 88. Meeeeeeee eee eeeeeeeee eee 8eee ee 88°M eeeeee eee eeeeee eee eeeeee ee 8°M eee eee eeeeeeee eeeeeee eee e eeeeeee 8.8e. Mee eeeeeeee ee eeeeee M8-eeee MeMM eeeeeeee eee eeeeeee; eeeee: 88%.

References


Cookie-Einstellungen