Isoprene Moiety Research Articles

REGIOSELECTIVE ADDITION OF CARBONYL COMPOUNDS TO ISOPRENE COORDINATED TO Zr

Abstract ZrCp2(isoprene) reacts with aliphatic aldehydes, ketones or nitriles regioselectively on C1-carbon of the isoprene moiety to give novel 2-oxa- or 2-aza-metallacycles which release alcohols or ketones respectively on hydrolysis. In contrast, ZrCH3(η1-methylallyl)Cp2, Ti(η3-methylallyl)Cp2, and [MgCH2C(CH3)=CHCH2]n reacted with acetone on the C3-carbon of the methylallyl or the isoprene unit.

Synthesis of isoprenoid natural products from β-keto esters

The anions of β-keto esters were reacted with diethyl phosphorochloridate to yield the corresponding enol phosphate. These enol phosphates were coupled with lithium dimethylcuprate to give the resulting β-methyl α, β-unsaturated ester stereoselectively and in good yield. When combined with the β-alkylation of the β-keto ester dianions this overall sequence results in the stereoselective and regioselective incorporation of an isoprene moiety in a synthetic sequence. This transformation has been applied in the synthesis of ( E,E)-10-hydroxy-3,7-dimethyldeca-2,6-dienoic acid (butterfly compound), Latia luciferin, and mokupalide.