A Novel Route to the Marasmane Skeleton via a Tandem Rearrangement−Cyclopropanation Reaction. Total Synthesis of (+)-Isovelleral
journal contributionposted on 08.03.2001, 00:00 by Roel P. L. Bell, Joannes B. P. A. Wijnberg, Aede de Groot
A general and efficient route to the marasmane skeleton is described. Total syntheses of two simple marasmanes (35 and 37) in racemic form were achieved using a MgI2-catalyzed rearrangement−cyclopropanation reaction of trimethylsilyl enol ether 31 derived from naphthalenone 30. The reaction proceeds in high yield with complete diastereoselectivity and does not require the use of special cyclopropanation reagents. Application of this novel route to the marasmane framework was extended to the synthesis of naturally occurring (+)-isovelleral (41).