p-Toluenesulfonic acid → HCID 66930311, compound

Participants

Reaction Conditions

Reaction Steps

Compound 12a (7.6 g) was dissolved dry methanol (100 mL). Trimethyl orthoformate (30 mL) and pTsOH (0.2 g) was added at rt under a nitrogen atmosphere. The mixture was heated at 60° C. for 8 hours. Once the reaction was deemed complete according to TLC, it was cooled to rt and concentrated in vacuo. The crude product was purified by column chromatography over silica gel eluting with ethyl acetate-heptane (1:4) to afford after concentration in vacuo the ketal 12b as a clear oil (5.9 g, 71% over 2 steps); ESI+, m/z: 382 (M+ —OMe).

Provenance & Evidence