Synthesis of (+)-podocarp-8(14)-en-13-one and methyl-(+)-13-oxo-podocarp-8(14)-en-18-oate from abietic acid

Synthesis and biological evaluation of abietic acid derivatives

“…The resulting residue was chromatographed on silica (9:1 hexane-EtOAc as eluant) to give 25 g (56%) of the isomerized ester 6 as an orange oil. The 1 H NMR and EIMS data agree with those reported in the literature [10]. (7) A suspension of LiAlH 4 (2.10 g, 58 mmol) in tetrahydrofuran (45 mL) was stirred as ester 6 (3.1 g, 9.8 mmol) in tetrahydrofuran (15 mL) was added.…”

“…The synthesis of the C18-functionalized abietanes used in this work begins with the preparation of the required methyl ester 2 from commercial (À)-abietic acid, following a reported procedure (Scheme 1) [10]. Thus, abietic acid 1 was esterified by treatment with lithium hydroxide and methyl sulfate to give ester 2 in quantitative yield.…”

“…Next, the conjugated double bonds present in ester 2 were isomerized using a known protocol [10] with few modifications (Scheme 1). Thus, methyl abietate (2) was treated with 33% HBr in acetic acid and the resulting bromo derivatives were heated in DMF at 80 C in the presence of lithium hydroxide to afford compound 6 in 56% overall yield.…”

Aromatic abietane diterpenoids: total syntheses and synthetic studies

“…27 Thus, abietic acid (1) was converted into methyl 15-hydroxydehydroabietate (128), via known methyl abieta-8,13(15)-dien-18-oate (127), 28 by treatment with SeO 2 . Methyl dehydroabietate (26) was used for the synthesis of picealactone A (130a) and the 15-hydroxy derivative 128 for the synthesis of picealactone B (130b).…”

Conversion of a Cyclic α,β-Unsaturated Ketone into a Tertiary Dienyl Hydroperoxide: Application to the First Hemisynthesis of 15-Hydroperoxyabietic Acid

“…19 Pure abietic acid was converted into the diene compound 7 following the procedure described by Arno and coworkers. 20 In their developed methodology to synthesize diterpene derivatives from abietic acid, the exocyclic carboncarbon double bond of 7 was cleaved by partial ozonolyzis to give a b,g-unsaturated ketone. It was then necessary to carefully monitor the ozone flow in order to avoid the cleavage of both tetrasubstituted double bonds in compound 7.…”