Monoterpene synthesis via alkenylidenecyclopropanes: Acid- and base-catalysed rearrangements

✍ Scribed by Leslie Crombie; Peter J. Maddocks; Gerald Pattenden

• Publisher: Elsevier Science
• Year: 1978
• Tongue: French
• Weight: 165 KB
• Volume: 19
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(00)70551-x

✦ Synopsis

Considerable effort has been expended towards developing methods for the synthesis of monoterpenes by head-to-tail linking of isopentane units. 1

We were attracted by the possibility of accomplishing this objective via the elaboration of Cl0 -cyclopropane intermediates (e.g. 1 and 21, obtained from the combination of a C5-carbene and an appropriate C5-alkene substrate. In this Letter, we report the results of acidand base-catalysed rearrangements of the ClO-alkenylidenecyclopropanes (4a-2) prepared by addition of the allene carbene (3)2 to 2-methylbut-l-en-3-yne, 3 isoprene, 4 and 2-methylbut-lene 5 respectively.