Conjugate addition-aldol approach to the simple bicyclic-diynene core structure found in the esperamicins and calicheamicins
摘要:
The stable 12-beta-hydroxybicyclo[7.1.0] diynene core 15 has been prepared stereospecifically. The key step consists of conjugate addition of dimethylaluminum benzenethiolate to enone aldehyde 12 followed by an in situ titanium isopropoxide assisted aldol cyclization to produce alcohol 13 as a single isomer.
Synthesis of a Protected (±)-Calicheamicinone Derivative by Sequential Introduction of Functionality into the Bicyclo[7.3.1]enediyne Core Structure
作者:Philip Magnus、Gregory F. Miknis、Neil J. Press、Didier Grandjean、G. Mark Taylor、John Harling
DOI:10.1021/ja970743t
日期:1997.7.1
The core bicyclo[7.3.0]enediyne 3 has been synthesized from the protected cyclohexane-1,2-dione 6 and enediyne component 9. Conversion of 20 into more highly functionalized enediynes was accomplished by oxidation and amination to give 27. Protection of 27, and conversion into 31, gave on treatment with (MeO)2P(O)CH2CO2Me the lactone 32, which was transformed into the trisulfide 39. All attempts to