Biomedical subjects

Andrew E Greene

Publications and source records attributed to Andrew E Greene.

21 records · Page 2Linked to original sources

PubMed2002

First comprehensive bakkane approach: stereoselective and efficient dichloroketene-based total syntheses of (+/-)- and (-)-9-acetoxyfukinanolide, (+/-)- and (+)-bakkenolide A, (-)-bakkenolides III, B, C, H, L, V, and X, (+/-)- and (-)-homogynolide A, (+/-)-homogynolide B, and (+/-)-palmosalide C.

Cycloaddition of dichloroketene with dimethylcyclohexenes has been used as the key reaction in an efficient, general approach to the bakkanes. New methods and methodologies that have been developed in this work include spiro beta-methylene-gamma-butyrolactonizations, a vicinal dicarboxylation, an angelic ester preparation, a transesterification, an epoxy ketone double reduction, and a retro aldol-aldol approach to low-energy aldol isomers.

4-Butyrolactone↗

PubMed2002

Synthetic approach to hypoxyxylerone, novel inhibitor of topoisomerase I.

[reaction: see text] A potential route to the topoisomerase I inhibitor hypoxyxylerone is demonstrated by a highly convergent synthesis of the penta(O-methyl) derivative. The key step in the approach is an anionic homo-Fries rearrangement, little used to date in natural product synthesis and employed here for the first time with a dinaphthalenic substrate, to access the pentacyclic system of hypoxyxylerone.

Cyclization↗

PubMed2002

New electron-deficient chiral phosphines: (4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl] substituted amines.

Three chiral electron-deficient phosphine ligands, [(4R,15R)-,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]diethylamine, C(12)H(20)F(6)N(3)O(4)PS(2), (IIIa), [(4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]dimethylamine, C(10)H(16)F(6)N(3)O(4)PS(2), (IIIb), and bis[(4R,5R)-1,3-bis(trifluoromethanesulfonyl)perhydro-1,3,2-benzodiazaphosphol-2-yl]methylamine, (IV), as the chloroform solvate, C(17)H(23)F(12)N(5)O(8)P(2)S(4).0.98CHCl(3), have been prepared from (1R,2R)-N,N'-bis(trifluoromethanesulfonyl)-1,2-cyclohexanediamine and diethyl phosphoramidous dichloride, dimethyl phosphoramidous dichloride or methyl imidodiphosphorus tetrachloride. The pi-acceptor abilities of these new types of ligands have been evaluated by X-ray determination of the P-N bond lengths; it has been found that the most promising ligand is the bis(phosphine) (IV).

Journal Article↗