Approach towards an EPC-synthesis of nodusmicin - IV. Construction of the highly hindered trisubstituted double bond of nodusmicin - IV. Construction of the highly hindered trisubstituted double bond of nodusmicin

Article abstract of DOI:10.1016/S0040-4039(97)01521-9

The highly substituted subunit 6 of our convergent synthesis of nodusmicin was prepared utilizing Evans' oxazolidinone protocol. Compound 6 was then adjoined to the decalin subunit 7 using Martin's olefination method. To improve on the formation of the hindered trisubstituted double bond, the following model reactions were devised: reductive coupling of ester and keto functionality of tricycle 16 led to the α-hydroxyketone, which was converted to the cyclic sulfate 19 via the diol. Sodium naphthalide then converted 19 to the olefins 20.