A concise total synthesis of arizonins B1 and C1

A concise and efficient total synthesis of arizonins B1 and C1 is reported. A key building block alkyne is synthesized from a-glucono-S-lactone and used in the Dotz benzannulation reaction to construct the naphthalene unit. An oxa-Pictet-Spengler reaction gave the pyran ring while an H2SO4 mediated isomerization set the correct stereochemistry of the target molecules. Alternatively, a direct anti-pyran stereochemistry was prepared in a TFA solvent. The synthesis is competitive to previous reports and marks the first enantioselective synthesis of arizonin B1. (C) 2013 Elsevier Ltd. All rights reserved.