Total syntheses of two Isodon diterpenes, isorosthin L and isoadenolin I, are reported. The synthetic strategy features a quick assembly of two simple building blocks through a diastereoselective intermolecular aldol reaction and a subsequent radical cyclization for efficient construction of a rather complex advanced intermediate bearing a quaternary stereocenter present in all Isodon diterpenes. Oxidative cleavage of the CÀ C bond in the cyclopentane enabled the conversion to a lactone moiety which is desired for the construction of the molecular skeleton through reductive coupling with an aldehyde carbonyl group.

Leucosceptroids are sesterterpenoids with potent antifeedant and antifungal activities. An efficient stereoselective construction of the highly congested [5,6,5] tricyclic framework of leucosceptroid H is presented. This framework bearing eight contiguous stereogenic centers, including three tetrasubstituted ones, could serve as a common intermediate for the collective total synthesis of the leucosceptroid family of natural products. Letter pubs.acs.org/OrgLett

Total syntheses of two Isodon diterpenes, isorosthin L and isoadenolin I, are reported. The synthetic strategy features a quick assembly of two simple building blocks through a diastereoselective intermolecular aldol reaction and a subsequent radical cyclization for efficient construction of a rather complex advanced intermediate bearing a quaternary stereocenter present in all Isodon diterpenes. Oxidative cleavage of the CÀ C bond in the cyclopentane enabled the conversion to a lactone moiety which is desired for the construction of the molecular skeleton through reductive coupling with an aldehyde carbonyl group.

A highly diastereoselective synthesis of the ABD skeleton of meliacarpinin B is presented.