A Stereoselective Total Synthesis of (plusmn;)-Callitrisic Acid

Abstract

Callitrisic acid (1, 4-epidehydroabietic acid) was isolated from the Australian white cypress pine Callitris columelaris in 1967.^2,3 allistrisic acid (1) was previously synthesized by Haworth and Barker;⁴ Sharma, Ghatak, and Dutta;⁵ Mori and Matsui⁶; and Pelletier and Herald.⁷ Interestingly enough Haworth and Barker's synthesis (the first total synthesis of a diterpenoid natural product) occurred 28 years before callitrisic acid (1) was isolated. We wish to report a short and highly stereoselective total synthesis of (±)-callitrisic acid (1).