Synergy of prediction rule and total synthesis in solving the stereochemical puzzle of eucalactam B

The absolute configurations of the fungal-derived reduced polyketide eucalactam B were initially predicted using the “Biochemistry-based rule” and later confirmed through its first successful total synthesis. This accomplishment involved key reactions such as Brown crotylation, the Paterson anti-aldol reaction, cross-metathesis, and macrolactamization, furnishing eucalactam B in 19 linear steps, with an overall yield of 6.0%. The high degree of alignment between the synthetic compound and the natural product provided strong validation for the accuracy of the “Biochemistry-based rule” in predicting the absolute configurations of fungal-derived reduced polyketides.