117. Short Synthesies of (+/-)-Grandisol and (+/-)-Lineatin via a Common Intermediate

Article abstract of DOI:10.1002/hlca.19870700510

A 6-step synthesis of (+/-)-grandisol (1) is presented, which involves dichloroketene addition to 3-methyl-3-butenyl acetate (4), reductive dechlorination of the adduct 6 to the ketone 7 and saponification to 8, aldolization of 7 or 8 with acetone and cyclization to the bicyclic ketone 9, Wolff-Kishner reduction to 14, and finally ring opening to 1.Since 9 is a known intermediate of the synthesis of (+/-)-lineatin (2), the latter can now be obtained in 6 steps.