Asymmetric synthesis of (+)-altholactone: a styryllactone isolated from various Goniothalamus species.
The asymmetric total synthesis of (+)-altholactone (1), a member of the styryllactone family of natural products displaying cytotoxic and antitumor activities, is described. Key steps include a RAMP-hydrazone alpha-alkylation (RAMP=(R)-1-amino-2-methoxymethylpyrrolidine) of 2,2-dimethyl-1,3-dioxan-5-one, a boron-mediated aldol reaction, a six- to five-membered ring acetonide shuffling, an oxidative 1,5-diol to delta-lactone conversion and a stereoselective ring-closure to generate the annulated tetrahydrofuran moiety with inversion of configuration.
Enders
Dieter
D
Institute of Organic Chemistry, RWTH Aachen, Landoltweg 1, 52074 Aachen, Germany. Enders@RWTH-Aachen.de
Barbion
Julien
J
D000970:Antineoplastic Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D054335:Goniothalamus / Q000737:chemistry; D008968:Molecular Conformation; D011753:Pyrones / Q000138:chemical synthesis* / Q000737:chemistry / Q000302:isolation & purification; D013237:Stereoisomerism
D000970:Antineoplastic Agents; D005663:Furans; D011753:Pyrones; C459359:altholactone