Studies Directed Towards the Total Synthesis of (+)-Himbacine
摘要:
A convergent strategy towards himbacine (1), involving a Julia coupling between aldehyde 5 and sulfone 6 was found to be ineffective. The aldehyde 5 was synthesized via the thermal intramolecular cycloaddition of 4 with preferred formation of the endo-adduct. The Diels-Alder precursor 4 was obtained from butenolide 7, the result of a single-step condensation between the enoate derived from the (Z)-conjugated olefin 12 and 2-acetoxypropanal. In the context of the synthesis of sulfone 6 Taber's method for the synthesis of 2,6-trans-disubstituted piperidine was adapted towards a large scale synthesis of 49, a useful intermediate for the synthesis in this area.
Studies directed towards the total synthesis of (±)-himbacine
作者:Govert De Baecke、Pierre J. De Clercq
DOI:10.1016/0040-4039(95)01520-5
日期:1995.10
The synthesis of aldehyde 11a is reported based upon the intramolecular Diels-Alder reaction of triene 10, the butenolide-diene part of which was obtained in one step via the condensation of the enolate derived from the (Z)-enoate ester 5 with 2-acetoxypropanal. Aldehyde 11a possesses the correct stereochemistry of the tricyclic part of himbacine, an important muscarine receptor antagonist.
Studies Directed Towards the Total Synthesis of (+)-Himbacine
作者:Sven Hofman
DOI:10.1055/s-1998-5928
日期:1998.3
A convergent strategy towards himbacine (1), involving a Julia coupling between aldehyde 5 and sulfone 6 was found to be ineffective. The aldehyde 5 was synthesized via the thermal intramolecular cycloaddition of 4 with preferred formation of the endo-adduct. The Diels-Alder precursor 4 was obtained from butenolide 7, the result of a single-step condensation between the enoate derived from the (Z)-conjugated olefin 12 and 2-acetoxypropanal. In the context of the synthesis of sulfone 6 Taber's method for the synthesis of 2,6-trans-disubstituted piperidine was adapted towards a large scale synthesis of 49, a useful intermediate for the synthesis in this area.