Jones reagent (1.4 M CrO3 in 2.2 M H2SO4 aqueous solution) was added dropwise to a 1 mL acetone solution containing 0.2 mmol of compound 6 (CAS: 125184-95-4) at 0 °C. The reaction mixture was slowly warmed to room temperature and stirred continuously until complete consumption of Feedstock 6 was confirmed by thin layer chromatography (TLC) monitoring. Upon completion of the reaction, water and dichloromethane (CH2Cl2) were added to the mixture for extraction. The organic layer was separated and washed with distilled water and subsequently dried with anhydrous magnesium sulfate (MgSO4). The solvent was evaporated under reduced pressure to afford the target product 2-((1R,4R,4aS,8aR)-4,7-dimethyl-1,2,3,4,4a,5,6,8a-octahydronaphthalen-1-yl)acrylic acid in quantitative yield (confirmed by LC/MS). Compound 2 can be further converted to DHAA (3) according to Roth and Acton in Journal of the Chemical Society, Chemical Communications (1989, 24, 1998) or by catalytic hydrogenation (see Example 4).