ABSTRACT
Tetralone esters (4a–c) on hydroxy methylation with ethyl formate yielded 5a–c which on reduction with sodium borohydride followed by hydrolysis gave dihydroxy acid 8a–c. Base-catalysed cyclisation of 8a–c using p-toluene sulfonyl chloride gave β-apopicropodophyllin analogues (3a–c) in quantitative yield.