ABSTRACT
An enantiospecific and stereoselective total synthesis of the natural product (+)-crispine A has been demonstrated employing a Pictet-Spengler bis-cyclization reaction between commercially available (R)-(-)-methyl 2-amino-3-(3,4-dimethoxyphenyl)propanoate and 4-chloro-1,1-dimethoxybutane to preferentially provide the cis tricyclic adduct. Decarboxylation by a convenient two-step protocol provided the enantiopure natural product in three steps with an overall isolated yield of 32% from the amino acid. The unnatural antipode (-)-crispine A was similarly prepared in three steps from the commercially available (S)-(+)-amino acid.
Subject(s)
Isoquinolines/chemistry , Isoquinolines/chemical synthesis , Biological Products/chemical synthesis , Biological Products/chemistry , Stereoisomerism , Substrate Specificity , Tyrosine/chemistryABSTRACT
A variety of functionalized penta-arylcorannulene derivatives were prepared in high yields and high chemoselectivity by a cross-coupling reaction between sym-pentachlorocorannulene and substituted arylboronic acids using Fu's Pd(0) catalyst. This approach provides a general entry to penta-substituted corannulene derivatives, which are useful building blocks for various structures of high complexity, such as pentagonal dendrimers, synthetic capsids, and discotic liquid crystals. This was demonstrated here by the facile synthesis of a third generation pentagonal dendrimer.
Subject(s)
Dendrimers/chemical synthesis , Polycyclic Aromatic Hydrocarbons/chemistry , Catalysis , Dendrimers/chemistry , Molecular Structure , StereoisomerismABSTRACT
Acylfulvenes, a class of semisynthetic analogs of Illudin S, show high toxicity toward prostate cancer cells. Here we probe the effect of changes in hydrophilic character of the analogs.
