PROCESS FOR THE PREPARATION OF CALANOLIDE PRECURSORS

摘要

A compound of formula (I) wherein R<1>, R<2>, R<3>, R<4> and R<6> each represent H or an organic group of up to 20 C atoms, or any pair of R<2> and R<3> or R<2> and R<6> or R<4> and R<6> forms a cyclic group, and R<5>SO2 is a cleavable protecting group in which R<5> is an organic group of up to 20 C atoms. These compounds are useful as intermediates in the synthesis of calanolide A and related antiviral compounds.