Non-iterative Asymmetric Synthesis of C15 Polyketide Spiroketals
作者:Kai Meilert、George R. Pettit、Pierre Vogel
DOI:10.1002/hlca.200490136
日期:2004.6
this being due to the tricyclic nature of (−)-20 (methyl pyranoside formation). Compound (−)-19 was converted similarly into the (4′S)-epimeric tricyclic spiroketal (−)-21 that also adopts a similar (3S)-configuration and conformation. Spiroketals (−)-20, (−)-21 and analog (−)-23, i.e., (1R,3S,4′R,5R,6′R)-3′,4′,5′,6′-tetrahydro-6′-[(2S)-2-hydroxybut-3-enyl]-7-methoxyspiro[2,6-dioxabicyclo[3.3.1]nonane-3