6-Protoilludene synthesis

A modern variant is the intramolecular magnesium-ene reaction, e.g. the reaction of the alkene-allylic-Grignard compound 9 to give the five-membered ring product 10. This reaction proceeds regio- and stereoselectively, and is a key step in a synthesis of the sesquiterpenoid 6-protoilludene ... 

Highly diaslereocontrolled formation of a cM-l,2-disubstituted five-membered ring was again observed in the key step (105) (106) of the synthesis of ( )-6-protoilludene (111) (Scheme 24). Cop-... 

---