Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• -tridecylbenzoic acid was developed that starts directly from the anacardic acid component of natural cashew nutshell liquid (CNSL). Natural CNSL contains 60–70% of anacardic acid as a mixture of several double bond isomers. The anacardic acid component was converted into a uniform starting material by ethenolysis

• subsequent hydrogenation step. Overall, the target compound was obtained in an overall yield of 61% based on the unsaturated anacardic acid content and 34% based on the crude CNSL. Keywords: cashew nutshell liquid; cross-metathesis; renewable feedstock; sustainable chemistry; tyrosinase inhibitor

• ; Introduction Cashew nutshell liquid (Scheme 1) is an ideal renewable feedstock. This non-edible industrial waste product, derived from the cashew nut processing, is abundant available and cheap [1][2][3]. The annual production of cashew nuts with shell reached 4.9 million tons in 2016 [4], leading to an