110965-88-3Relevant articles and documents
STEREOSELECTIVE TOTAL SYNTHESIS OF THE CEMBRANOLIDE DITERPENE ANISOMELIC ACID
Marshall, James A.,DeHoff, Bradley S.
, p. 4873 - 4876 (1986)
A highly stereoselective total synthesis of the cembranolide diterpene anosomelic acid has been achieved via a convergent route.Macrocyclization was effected by a (Z)-selective intramolecular Horner-Emmons condensation.
CEMBRANOLIDE TOTAL SYNTHESIS. ANISOMELIC ACID
Marshall, James A.,DeHoff, Bradley S.
, p. 4849 - 4860 (2007/10/02)
The stereoselective total synthesis of (+/-)-anisomelic acid (34) has been achieved starting from aldehyde 7, the ozonolysis product of geranyl acetate.Two key steps ensured the stereoselectivity of the synthesis.The first entailed a highly anti-selective addition of the allyltitanium derived from carbamate 15 to aldehyde 5 affording the enol carbamate allylic alcohol 16.The second was a highly (Z)-selective Horner-Emmons cyclization of the derived phosphono ester aldehyde 25 leading to the conjugated ester 27.Further conversion led to the crystalline lactone 30 whose structure was confirmed through single crystal X-ray analysis.Equilibration of the conjugated double bond of 30 gave rise to a 1:1 mixture of the (Z) and (E) isomers.This result was foretold by molecular mechanics calculations.
